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Word roots explorer

Medical terms are built from a small set of word parts. Learn what each part means and where it comes from, then see the words that use it.

Roots and combining forms (28)

The core of a medical word, usually naming a body part or substance. A combining form is a root plus a linking vowel, written cardi/o: use cardi- before a vowel (carditis) and cardio- before a consonant (cardiomyopathy).

aden/o gland

Root / combining form · Greek adḗn ‘gland’

Dictionary.com notes it is akin to Latin inguen, 'groin'.

Terms built with aden/o
AdenomaAdenopathy
Other dictionary terms with this spelling (origin not yet checked)
Lymphadenopathy
Sources: Dictionary.com: adeno- · Source-checked 2026-10-27 · editor review pending

angi/o vessel (usually a blood vessel)

Root / combining form · Greek angeîon ‘vessel, container’

From Greek áng(os) 'vessel, vat, shell' with a diminutive ending.

Terms built with angi/o
Angiography
Other dictionary terms with this spelling (origin not yet checked)
Angioplasty
Sources: Dictionary.com: angio- · Source-checked 2026-10-27 · editor review pending

arthr/o joint

Root / combining form · Greek árthron ‘a joint’

arthr- is used before a vowel (arthralgia). Dictionary.com notes it is akin to Latin artus.

Terms built with arthr/o
ArthritisArthralgiaOsteoarthritis
Other dictionary terms with this spelling (origin not yet checked)
Rheumatoid Arthritis
Sources: Dictionary.com: arthro- · Source-checked 2026-10-27 · editor review pending

cardi/o heart

Root / combining form · Greek kardía ‘heart’

cardi- is used before a vowel (carditis). In words such as tachycardia it appears in the ending -cardia.

Terms built with cardi/o
TachycardiaBradycardiaCarditisPericarditisEndocarditisMyocarditisCardiomegalyCardiomyopathy
Other dictionary terms with this spelling (origin not yet checked)
CardiacMyocardialEchocardiographyPericardiumCardiac Tamponade
Sources: Dictionary.com: cardio- · Wiktionary: cardio- · Source-checked 2026-10-27 · editor review pending

cyst/o bladder; cyst or sac

Root / combining form · Greek kústē

Refers to the urinary bladder or to any cyst or sac.

No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
CholecystitisCyst
Sources: Wiktionary: cysto- · Source-checked 2026-10-27 · editor review pending

dermat/o skin

Root / combining form · Greek dérma (stem dermat-) ‘skin’

Also appears as derm/o and as the ending -derma (scleroderma).

Terms built with dermat/o
Scleroderma
Other dictionary terms with this spelling (origin not yet checked)
Xeroderma
Sources: Dictionary.com: dermato- · Source-checked 2026-10-27 · editor review pending

encephal/o brain

Root / combining form · Greek enképhalos ‘brain’

encephal- is used before a vowel (encephalitis).

Terms built with encephal/o
EncephalitisEncephalopathy
Sources: Dictionary.com: encephalo- · Source-checked 2026-10-27 · editor review pending

enter/o intestine

Root / combining form · Greek énteron ‘intestine’

enter- is used before a vowel.

Terms built with enter/o
Gastroenteritis
Other dictionary terms with this spelling (origin not yet checked)
EnteralParenteral
Sources: Dictionary.com: entero- · Source-checked 2026-10-27 · editor review pending

haem/o · haemat/o blood

Root / combining form · Greek haîma (stem haimat-) ‘blood’

Entered medical vocabulary through New Latin. British spelling haem-/haemat-; US spelling hem-/hemat-.

Terms built with haem/o · haemat/o
HaematomaHaematuriaHaemolysis
Other dictionary terms with this spelling (origin not yet checked)
HaemoptysisHaemorrhageHaematemesisHaematocritHaemoglobinHaemostasisSubarachnoid HaemorrhageSubconjunctival Haemorrhage
Sources: Dictionary.com: hemo- · Dictionary.com: hemato- · Source-checked 2026-10-27 · editor review pending

hepat/o liver

Root / combining form · Greek hêpar (stem hēpat-) ‘liver’

hepat- is used before a vowel (hepatitis).

Terms built with hepat/o
HepatitisHepatomegaly
Other dictionary terms with this spelling (origin not yet checked)
Hepatosplenomegaly
Sources: Dictionary.com: hepato- · Source-checked 2026-10-27 · editor review pending

leuk/o (leuc/o) white; white blood cell

Root / combining form · Greek leukós ‘white, bright’

leuco- is the traditional British form and a common variant; leuk- is used before a vowel.

Terms built with leuk/o (leuc/o)
LeukaemiaLeukopeniaLeukocytosis
Sources: Dictionary.com: leuko- · Source-checked 2026-10-27 · editor review pending

lip/o fat

Root / combining form · Greek lípos ‘fat’

lip- is used before a vowel.

Terms built with lip/o
Lipoma
Sources: Dictionary.com: lipo- · Source-checked 2026-10-27 · editor review pending

lith/o stone

Root / combining form · Greek líthos ‘stone’

Also the ending -lith (nephrolith).

No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
NephrolithiasisCholelithiasis
Sources: Dictionary.com: litho- · Source-checked 2026-10-27 · editor review pending

my/o muscle

Root / combining form · Greek mŷs ‘mouse; muscle’

The same Greek word meant both 'mouse' and 'muscle'. my- is used before a vowel (myalgia).

Terms built with my/o
MyocarditisCardiomyopathyMyalgiaMyopathy
Sources: Dictionary.com: myo- · Source-checked 2026-10-27 · editor review pending

neur/o nerve; nervous system

Root / combining form · Greek neûron ‘nerve’

Dictionary.com notes the Greek word is akin to Latin nervus.

Terms built with neur/o
NeuralgiaNeuritisNeuropathy
Sources: Dictionary.com: neuro- · Source-checked 2026-10-27 · editor review pending

oste/o bone

Root / combining form · Greek ostéon ‘bone’

oste- is used before a vowel (osteitis).

Terms built with oste/o
Osteoarthritis
Other dictionary terms with this spelling (origin not yet checked)
OsteoporosisOsteomyelitis
Sources: Dictionary.com: osteo- · Source-checked 2026-10-27 · editor review pending

ot/o ear

Root / combining form · Greek oûs (combining form ōto-) ‘ear’

ot- is used before a vowel (otitis).

Terms built with ot/o
Otosclerosis
Sources: Dictionary.com: oto- · Source-checked 2026-10-27 · editor review pending

pneum/o lung; air

Root / combining form · Greek pneúmōn / pneûma ‘a lung / wind, breath’

Two related Greek words lie behind this form: pneúmōn 'lung' and pneûma 'wind, breath'.

No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
PneumoniaPneumothorax
Sources: Wiktionary: pneumo- · Source-checked 2026-10-27 · editor review pending

rhin/o nose

Root / combining form · Greek rhī́s (combining form rhīno-) ‘nose’

Wiktionary gives naso- as a synonym.

Terms built with rhin/o
Rhinitis
Sources: Wiktionary: rhino- · Source-checked 2026-10-27 · editor review pending

scler/o hard; sclera

Root / combining form · Greek sklērós ‘hard’

In anatomy it can also refer to the sclera (white of the eye).

Terms built with scler/o
SclerosisSclerodermaOtosclerosis
Other dictionary terms with this spelling (origin not yet checked)
Atherosclerosis
Sources: Wiktionary: sclero- · Source-checked 2026-10-27 · editor review pending

ur/o urine; urinary tract

Root / combining form · Greek oûron ‘urine’

Not to be confused with a separate uro- meaning 'tail' (Greek ourá). See also the suffix -uria.

Terms built with ur/o
DysuriaUraemia
Sources: Dictionary.com: uro- · Source-checked 2026-10-27 · editor review pending

Prefixes (14)

Placed before a root to modify its meaning: position, number, speed, quantity or negation.

a-, an- not, without

Prefix · Greek a- (before consonants), an- (before vowels) ‘not, without’

an- is used before vowels and sometimes h (anaemia, anuria).

Terms built with a-, an-
AnuriaAnaemia
Sources: Wiktionary: a- · Source-checked 2026-10-27 · editor review pending

anti- against; counteracting

Prefix · Greek anti- ‘against’
No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
AntibioticAnticoagulant
Sources: Wiktionary: anti- · Source-checked 2026-10-27 · editor review pending

hemi- half

Prefix · Greek hēmi- ‘half’

Cognate with Latin semi-.

Terms built with hemi-
Hemiplegia
Other dictionary terms with this spelling (origin not yet checked)
Hemianopia
Sources: Dictionary.com: hemi- · Source-checked 2026-10-27 · editor review pending

neo- new, recent

Prefix · Greek néos ‘new’
No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
NeonatalNeonate
Sources: Dictionary.com: neo- · Source-checked 2026-10-27 · editor review pending

Suffixes (19)

Placed at the end of a word to name a condition, procedure or disease.

-aemia condition of the blood

Suffix · Greek haîma + -ia ‘blood + noun ending’

Formed in New Latin. US spelling -emia.

Terms built with -aemia
LeukaemiaHyperglycaemiaHypoglycaemiaUraemiaPolycythaemiaAnaemia
Other dictionary terms with this spelling (origin not yet checked)
BacteraemiaIschaemiaAzotaemiaDyslipidaemiaFungaemiaHyperkalaemiaHypernatraemiaHypoalbuminaemiaHypokalaemiaHyponatraemiaHypovolaemiaHypoxaemiaSepticaemiaThalassaemiaToxaemia
Sources: Wiktionary: -aemia · Source-checked 2026-10-27 · editor review pending

-algia pain

Suffix · Greek -algía (from álgos) ‘pain, suffering’

Borrowed via New Latin.

Terms built with -algia
ArthralgiaMyalgiaNeuralgia
Sources: Wiktionary: -algia · Source-checked 2026-10-27 · editor review pending

-ectomy surgical removal

Suffix · Greek ektomḗ ‘a cutting out’

From ek 'out' + témnō 'to cut'. Compare -tomy.

Terms built with -ectomy
Gastrectomy
Other dictionary terms with this spelling (origin not yet checked)
OophorectomySplenectomy
Sources: Wiktionary: -ectomy · Source-checked 2026-10-27 · editor review pending

-graphy writing, description; (in medicine) a recording or imaging procedure

Suffix · Greek -graphía (from graphḗ) ‘writing, drawing, description’

Reached English through French -graphie and Latin -graphia.

Terms built with -graphy
Angiography
Other dictionary terms with this spelling (origin not yet checked)
Echocardiography
Sources: Wiktionary: -graphy · Source-checked 2026-10-27 · editor review pending

-itis inflammation

Suffix · Greek -îtis ‘pertaining to’

In Greek this was an adjective ending meaning 'pertaining to'. Via New Latin it became the standard ending for inflammatory diseases.

Terms built with -itis
CarditisPericarditisEndocarditisMyocarditisHepatitisGastritisGastroenteritisArthritisOsteoarthritisNeuritisEncephalitisBronchitisRhinitis
Other dictionary terms with this spelling (origin not yet checked)
AppendicitisCellulitisCholecystitisMeningitisPancreatitisPeritonitisPhlebitisSinusitisTonsillitisVasculitisChondritisDiverticulitisEpiglottitisFolliculitisGlomerulonephritisGlossitisLaryngitisMastitisOrchitisOsteomyelitisPyelonephritisRheumatoid ArthritisSalpingitisSynovitisUlcerative ColitisUveitis
Sources: Wiktionary: -itis · Source-checked 2026-10-27 · editor review pending

-logy study of; branch of learning

Suffix · Greek

Came into English through loanwords from Greek, usually via Latin and French.

Terms built with -logy
Pathology
Other dictionary terms with this spelling (origin not yet checked)
GynaecologyAetiologySerology
Sources: Wiktionary: -logy · Source-checked 2026-10-27 · editor review pending

-oma tumour; mass

Suffix · Greek -ōma

Forms nouns for tumours or masses. Not every -oma is a tumour: a haematoma is a collection of blood.

Terms built with -oma
AdenomaLipomaHaematoma
Other dictionary terms with this spelling (origin not yet checked)
CarcinomaGlaucomaSarcomaLymphoma
Sources: Wiktionary: -oma · Source-checked 2026-10-27 · editor review pending

-osis abnormal condition; process; increase

Suffix · Greek -ōsis ‘state, abnormal condition, or action’

Borrowed via New Latin. Can mean a disease state (sclerosis), a process, or an increase (leukocytosis).

Terms built with -osis
LeukocytosisSclerosisOtosclerosis
Other dictionary terms with this spelling (origin not yet checked)
AnastomosisCirrhosisCyanosisEcchymosisFibrosisNecrosisOsteoporosisPsychosisStenosisThrombosisAcidosisAgranulocytosisAlkalosisAmyloidosisAnkylosisAortic StenosisAtherosclerosisEndometriosisDiabetic KetoacidosisKyphosisLordosisMononucleosisSarcoidosisScoliosisTuberculosis
Sources: Wiktionary: -osis · Source-checked 2026-10-27 · editor review pending

-penia deficiency

Suffix · Greek peníā ‘poverty, lack’
Terms built with -penia
LeukopeniaCytopenia
Other dictionary terms with this spelling (origin not yet checked)
Neutropenia
Sources: Wiktionary: -penia · Source-checked 2026-10-27 · editor review pending

-plegia paralysis

Suffix · Greek plḗssō ‘to strike’

Extracted from paraplegia (Greek paraplēgía).

Terms built with -plegia
Hemiplegia
Other dictionary terms with this spelling (origin not yet checked)
ParaplegiaQuadriplegia
Sources: Wiktionary: -plegia · Source-checked 2026-10-27 · editor review pending

-scopy viewing; examination

Suffix · Greek skopéō ‘to see’
Terms built with -scopy
Endoscopy
Other dictionary terms with this spelling (origin not yet checked)
ColonoscopyLaparoscopy
Sources: Wiktionary: -scopy · Source-checked 2026-10-27 · editor review pending

-tomy surgical incision; cutting

Suffix · Greek témnō ‘I cut’

-tomy means cutting into; -ectomy means cutting out.

No source-checked terms yet
Other dictionary terms with this spelling (origin not yet checked)
LaparotomyThoracotomyTracheotomy
Sources: Wiktionary: -tomy · Source-checked 2026-10-27 · editor review pending

By language of origin

The source language of each word part. Many Greek parts reached English through New Latin, the Latin used in early modern science and medicine. The modern clinical meaning can differ from the original sense.

Greek (59)

a-, an- not, withoutaden/o gland-aemia condition of the blood-algia painangi/o vessel (usually a blood vessel)anti- against; counteractingarthr/o jointbrady- slowbronch/o bronchus (airway to the lung)cardi/o heartcyst/o bladder; cyst or saccyt/o celldermat/o skindys- abnormal, difficult, painful, bad-ectomy surgical removalencephal/o brainendo- within, insideenter/o intestineepi- upon, above, near; aftergastr/o stomachglyc/o sugar; glucose-graphy writing, description; (in medicine) a recording or imaging procedurehaem/o · haemat/o bloodhemi- halfhepat/o liverhyper- over, abovehypo- under, below; less than normal-itis inflammationleuk/o (leuc/o) white; white blood celllip/o fatlith/o stone-logy study of; branch of learning-lysis breakdown; dissolution-megaly enlargementmy/o muscleneo- new, recentnephr/o kidneyneur/o nerve; nervous system-oma tumour; mass-osis abnormal condition; process; increaseoste/o boneot/o earpath/o disease; suffering-pathy disease; disorder-penia deficiencyperi- around, surrounding-plegia paralysispneum/o lung; air-pnoea breathingpoly- many, muchrhin/o nose-rrhoea flowscler/o hard; sclera-scopy viewing; examinationtachy- fast, rapidtherm/o heat-tomy surgical incision; cuttingur/o urine; urinary tract-uria condition of the urine

Greek and Latin (1)

-ia condition; disease (noun ending)

Latin (1)

sub- under, below

How origins are checked

Every word part and word origin shown with a breakdown is linked to the dictionary entry it was checked against. Each one carries a status:

  • Source-checked: compared with the cited dictionary entry, awaiting review by a medical editor.
  • Editor-verified: reviewed and signed off by an editor.
  • Unverified origin note: an older short note that has not yet been checked. It is shown with an “unverified” label.

Historical meanings are kept separate from the modern clinical definition. Word parts are never inferred from spelling alone. Spelling matches are listed separately and labelled.