Biology Prefixes - E

e- [from Latin e- out of, from] Out (epilation).

ec- [from Latin ex = Greek ek out of, from] Out, out of (eczema).

ec- or eco- or oec- or oeco- or oiko- [from Greek oikos habitation] (1) habitation; (2) relating to the environment (ecology).

echin- or echino- [from Greek echinos hedgehog or sea urchin] Spiny, pointed (echinate).

echo- [from Greek echo echo] Denotes repetition or echo (echolalia, echopraxia, echolocation).

ect- or ecto- [from Greek ecto outside] Outside, outer (ectotherm, ectopia, ectopic, ectopotomy, ectotoxemia).

ef- [from Latin ex out of, from] Out, away (efferent). Before roots and suffixes beginning with f the prefix ex- becomes ef-.

elaeo- or elaio- or eleo- [from Greek elaion oil] Denotes oil or oiliness (Elaeocarpus = a genus of evergreen plants with oily fruit).

elast- or elasto- [from Greek elastikos elastic] Elastic (elastin).

eleuther- or eleuther- [from Greek eleutheros free] Free (Eleutherodactylus).

elytr- or elytro- [from Greek elytron vagina] Vagina (elytritis, elytroptosis, elytrostenosis).

eme- or emet- or emeto- [from Greek emein to vomit] Vomiting (emetology).

emme- or emmen- or emmenio- or emmeno- [from Greek emmena menses] Menses (emmenagogue).

em- or en- [from Latin im-, in-] (1) in, into, within, inside (empyema); (2) to become (encyst).

encephal- or encephalo- [from Greek enkephalos brain] Brain, having to do with the brain (encephalitis).

end- or endo- or ento- [from Greek endon within] Within, inside (endotherm).

enter- or entero- [from Greek enteron intestine] Relating to the intestines (enteritis).

eo- [from Greek eos dawn] Denotes dawn; can mean (1) early like the dawn (Eocene); or (2) rose-colored like the dawn (eosin).

ep- or eph- or epi- [Greek epi upon] Upon (epidermis; epiphysis).

ependym- or ependymo- [Greek ependyma wrap] Denotes the ependyma (ependymitis).

epididym- or epididymo- [epi- + didym-] Denotes the epididymis (epidydymoorchitis).

epilepto- [from Latin epilepsia] Epilepsy (epileptology).

episio- [Greek episeion pudenda] Vulva (episioplasty).

equi- [Latin aequus level, even, equal, like] Equal, alike (equicaloric).

erg- or ergo- [Greek ergon work] Work (ergometer).

erythr- or erythro- [Greek erythros red] Red (erythrocyte).

esophag- or esophago- (British spelling: oesophago-) [from Greek oisophagos esophagus] Esophagus (esophagostenosis).

esthesi- (British spelling: aesthesi-) [from Greek aisthesis sensation, feeling] Denotes sensation (esthesiology).

eth- or etho- (1) ether; (2) ethyl.

ethmo- [from Greek ethmos sieve] (1) sieve (ethmoid); (2) ethmoid bone (ethmomaxillary).

ethn- or ethno- [from Greek ethnos nation] Denotes race or nation (ethnology).

etio- (British spelling: aetio-) [from Greek aetia cause] (1) cause (etiology); (2) created by the breaking down of the chemical compound specified by the stem (etioporphyrin).

eu- [from Greek eus good] True, pure, well (euplastic; eugenics).

ex- or exo- [Latin ex out of, from, because of, as a result of] Out of, outside of, from, because, external (excision, exosepsis).

exa- [prefix in International System of Units] 10¹⁸ (exaFLOPS).

excit- or excito- [from Latin excitare to excite] Stimulating (excitomuscular).

exter- or extero- [from Latin exterus outer, external, outward, far, foreign] External (exteroceptor).

extra- [Latin extra outside of, beyond, beside, except] On the outside, beyond (extradural).