E - Word Building Reference

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]

Word building [ E ]

Use this reference to see how common medical terms are created using the various prefixes, suffixes, and root words.

ectoblast

Prefix: ecto-
Prefix Definition: out; outside
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -blast
Suffix Definition: embryonic; immature cell
Definition: outer layer of an immature cell

ectoderm

Prefix: ecto-
Prefix Definition: out; outside
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -derm
Suffix Definition: skin
Definition: outermost layer of skin cells

ectopia

Prefix: ecto-
Prefix Definition: out; outside
1st Root Word: top/o
1st Root Definition: place; position; location
2nd Root Word:
2nd Root Word Definition:
Suffix: -ia
Suffix Definition: condition
Definition: condition of an abnormal location or position of an organ or
body part

ectopic pregnancy

Prefix: ecto-
Prefix Definition: out; outside
1st Root Word: top/o
1st Root Definition: place; position; location
2nd Root Word:
2nd Root Word Definition:
Suffix: -ic
Suffix Definition: pertaining to
Definition: fetus develops outside the uterus

ectoplasm

Prefix: ecto-
Prefix Definition: out; outside
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -plasm
Suffix Definition: formation; structure
Definition: outer layer of a cell

electrocardiogram

Prefix:
Prefix Definition:
1st Root Word: electr/o
1st Root Definition: electricity
2nd Root Word: cardi/o
2nd Root Word Definition: heart
Suffix: -gram
Suffix Definition: record
Definition: a record of electrical currents associated with the heart muscle

electrocardiograph

Prefix:
Prefix Definition:
1st Root Word: electr/o
1st Root Definition: electricity
2nd Root Word: cardi/o
2nd Root Word Definition: heart
Suffix: -graph
Suffix Definition: instrument for recording
Definition: instrument for recording electrical currents associated with
the heart muscle

encephalitis

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word:
2nd Root Word Definition:
Suffix: -itis
Suffix Definition: inflammation
Definition: inflammation of the brain

encephalocele

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word:
2nd Root Word Definition:
Suffix: -cele
Suffix Definition: hernia; swelling
Definition: hernia protrusion of brain substance

encephalogram

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word:
2nd Root Word Definition:
Suffix: -gram
Suffix Definition: record
Definition: record of electrical activity of the brain

encephalomalacia

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word:
2nd Root Word Definition:
Suffix: -malacia
Suffix Definition: softening
Definition: softening of brain tissue

encephalomeningitis

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word: mening/o
2nd Root Word Definition: meninges (membranes covering the spinal cord
and brain)
Suffix: -itis
Suffix Definition: inflammation
Definition: inflammation of the brain and meninges (membranes covering
the spinal cord and brain)

encephalomyelitis

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word: myel/o
2nd Root Word Definition: spinal cord; bone marrow
Suffix: -itis
Suffix Definition: inflammation
Definition: inflammation of the brain and spinal cord

encephalopathy

Prefix:
Prefix Definition:
1st Root Word: encephal/o
1st Root Definition: brain
2nd Root Word:
2nd Root Word Definition:
Suffix: -pathy
Suffix Definition: disease; emotion
Definition: disease of function of the brain is affected

endocrine

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -crine
Suffix Definition: secrete; separate
Definition: glands that secrete products into the blood

endocrinology

Prefix: endo-
Prefix Definition: in; within
1st Root Word: crin/o
1st Root Definition: secrete
2nd Root Word:
2nd Root Word Definition:
Suffix: -logy
Suffix Definition: study (process of)
Definition: study of glands that secrete products into the blood

endocytosis

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -cytosis
Suffix Definition: condition of cells; slight increase of numbers
Definition: cells absorb material outside their membranes

endogen

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -gen
Suffix Definition: substance that produces
Definition: substance (plant) that increases in size by internal growth

endoscope

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -scope
Suffix Definition: instrument for visual examination
Definition: instrument for visual examination in the body or its internal parts

endoscopy

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -scopy
Suffix Definition: visual examination
Definition: visual examination inside the body

endospore

Prefix: endo-
Prefix Definition: in; within
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -spore
Suffix Definition: reproductive element
Definition: asexual spore developed within a cell

endothermic

Prefix: endo-
Prefix Definition: in; within
1st Root Word: therm/o
1st Root Definition: heat
2nd Root Word:
2nd Root Word Definition:
Suffix: -ic
Suffix Definition: pertaining to
Definition: pertaining to absorption of heat or an organism that
generates heat

enterolysis

Prefix:
Prefix Definition:
1st Root Word: enter/o
1st Root Definition: intestines (usually small intestines)
2nd Root Word:
2nd Root Word Definition:
Suffix: -lysis
Suffix Definition: breakdown; separation; destruction; loosening
Definition: separation of intestinal adhesions

epicardium

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word: cardi/o
1st Root Definition: heart
2nd Root Word:
2nd Root Word Definition:
Suffix: -ium
Suffix Definition: structure; tissue
Definition: serous membrane that forms the innermost layer of the
pericardium and the outer surface of the heart

epidermis

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word: derm/o
1st Root Definition: skin
2nd Root Word:
2nd Root Word Definition:
Suffix:
Suffix Definition:
Definition: outer layer of the skin

epidural

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word: dur/o
1st Root Definition: dura matter
2nd Root Word:
2nd Root Word Definition:
Suffix: -al
Suffix Definition: pertaining to
Definition: pertaining to being on or around the dura matter

epilepsy

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -lepsy
Suffix Definition: seizure
Definition: unprovoked seizure

episclera

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word: scler/o
1st Root Definition: sclera (white of the eye)
2nd Root Word:
2nd Root Word Definition:
Suffix:
Suffix Definition:
Definition: outermost layer of the sclera

episiotomy

Prefix:
Prefix Definition:
1st Root Word: episi/o
1st Root Definition: vulva
2nd Root Word:
2nd Root Word Definition:
Suffix: -tomy
Suffix Definition: process of surgically cutting the opening of the vagina
Definition:

epistaxis

Prefix: epi-
Prefix Definition: above; upon; on
1st Root Word:
1st Root Definition:
2nd Root Word:
2nd Root Word Definition:
Suffix: -staxis
Suffix Definition: dripping; trickling
Definition: dripping; trickling; blood from the nose

erythrocyte

Prefix:
Prefix Definition:
1st Root Word: erythr/o
1st Root Definition: red
2nd Root Word:
2nd Root Word Definition:
Suffix: -cyte
Suffix Definition: cell
Definition: red blood cell

erythromelalgia

Prefix:
Prefix Definition:
1st Root Word: erythr/o
1st Root Definition: red
2nd Root Word: mel/o
2nd Root Word Definition: limb; limbs
Suffix: -algia
Suffix Definition: pain
Definition: condition of redness, swelling and/or pain of the limbs

esophageal

Prefix:
Prefix Definition:
1st Root Word: esophag/o
1st Root Definition: esophagus
2nd Root Word:
2nd Root Word Definition:
Suffix: -eal
Suffix Definition: pertaining to
Definition: pertaining to the esophagus

esthesia

Prefix:
Prefix Definition:
1st Root Word: esthes/o
1st Root Definition: nervous sensation
2nd Root Word:
2nd Root Word Definition:
Suffix: -ia
Suffix Definition: condition
Definition: condition of sensation and feeling sensibility

estrogen

Prefix:
Prefix Definition:
1st Root Word: estr/o
1st Root Definition: female
2nd Root Word:
2nd Root Word Definition:
Suffix: -gen
Suffix Definition: substance that produces
Definition: female steroid hormone produced by the ovaries

eukaryote

Prefix: du-
Prefix Definition: good; normal
1st Root Word: kary/o
1st Root Definition: nucleus
2nd Root Word:
2nd Root Word Definition:
Suffix: -ote
Suffix Definition: expand
Definition: cell with a true nucleus

excision

Prefix: ex-
Prefix Definition: out; away from
1st Root Word: cis/o
1st Root Definition: to cut
2nd Root Word:
2nd Root Word Definition:
Suffix: -ion
Suffix Definition: process
Definition: process of cutting out; away from

exophthalmos

Prefix: exo-
Prefix Definition: out; away from
1st Root Word: thalm/o
1st Root Definition: thalamus (eyeball)
2nd Root Word:
2nd Root Word Definition:
Suffix:
Suffix Definition: abnormal protrusion of the thalamus (eyeball)
Definition:

exoskeleton

Prefix: exo-
Prefix Definition: out; away from
1st Root Word: skelet/o
1st Root Definition: skeleton
2nd Root Word:
2nd Root Word Definition:
Suffix:
Suffix Definition:
Definition: external hard, protective covering on an animal

extradural

Prefix: extra-
Prefix Definition: outside
1st Root Word: dur/o
1st Root Definition: dura matter
2nd Root Word:
2nd Root Word Definition:
Suffix: -al
Suffix Definition: pertaining to
Definition: pertaining to the outside of dura matter, but within the skull

Increasing your understanding of medical terminology

Word Building Reference– This resource strengthens your understanding of medical terminology. See how common medical terms are created using the various prefixes, suffixes, and root words.

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n o p q r s t u v w x y z

Medical Terminology Intuitive Section
This section was developed for ‘speed learning’ of medical terminology.

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Additional references:

Prefixes denoting numbers
Prefixes denoting position and/or direction
Prefixes denoting measurement
Medical Terminology Noun Suffixes
Combining forms for color
Common Prefixes
Adjective Suffixes
Specialties and specialists med terms
Instruments, surgical, and diagnostic procedures
Negative prefixes
Common suffixes

Quick Introduction– provides an overview and introduction to medical terminology.
Medical Terms – rules governing singular versus plural versions of medical terms are described.

Alphabetical Listing (word building)