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Medical terminology is composed of a prefix, root word, and suffix:
Prefix: A prefix is placed at the beginning of a word to modify or change its meaning. Pre means "before." Prefixes may also indicate a location, number, or time.
Root: central part of a word.
Suffix: The ending part of a word that modifies the meaning of the word.
Additional resources:   [Intro to med terms] [Med terms rules] [Med term reference] [Word building reference]  [Practice Exams]

Alphabetical Listing of Med Terms

a b c d e f g h i j k l m
n o p q r s t u v w x y z

Medical Terminology Reference – O

obstetr/o   pregnancy; birth
ocul/o   eye
odont/o   tooth
odyn/o   pain
-oid   resembling; derived from
-ole   little; small
ole/o   oil
olecran/o   olecranon (elbow)
olig/o   scanty
om/o   shoulder
-oma   tumor; mass; fluid collection
omphal/o   umbilicus (navel)
onc/o   tumor
-one   hormone
one   mono, uni
one and a half   bi, di
onych/o   nail (of fingers or toes)
o/o   egg
oophor/o   ovary
-opaque   obscure
ophry/o   eyebrow
ophthalm/o   eye
-opia   vision condition
opisth/o   backward, behind
-opsia   vision condition
-opsy   view of
opt/o   eye; vision
optic/o   eye; vision
-or   one who
or/o   mouth
orch/o   testis
orchi/o   testis
orchid/o   testis
-orexia   appetite
organ/o   organ
orth/o   straight
osche/o   scrotum
-ose   full of; pertaining to; sugar
-osis   condition, usually abnormal
-osmia   smell
osphresi/o   sense of smell
ossicul/o   ossicle (small bone)
oste/o   bone
-ostosis   condition of bone
ot/o   ear
-otia   ear condition
-ous   pertaining to
ov/o   egg
ovari/o   ovary
ovul/o   egg
ox/o   oxygen
-oxia   oxygen
oxy-   swift; sharpp; acid
oxysm/o   sudden

For a quick overview and tutorial on medical terminology, check out our Introduction to Medical Terminology.


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