epi-

1.
a prefix occurring in loanwords from Greek, where it meant “upon,” “on,” “over,” “near,” “at,” “before,” “after” (epicedium; epidermis; epigene; epitome); on this model, used in the formation of new compound words (epicardium; epinephrine).
Also, ep-, eph-.
Origin
< Greek, prefixal use of epí, preposition and adv.
British Dictionary definitions for epi-

epi-

prefix
1.
on; upon; above; over: epidermis, epicentre
2.
in addition to: epiphenomenon
3.
after: epigenesis, epilogue
4.
near; close to: epicalyx
Word Origin
from Greek, from epi (prep)
Word Origin and History for epi-

word-forming element meaning "on, upon, above," also "in addition to; toward, among," from Greek epi "upon, at, close upon (in space or time), on the occasion of, in addition," from PIE *epi, *opi "near, at, against" (cf. Sanskrit api "also, besides;" Avestan aipi "also, to, toward;" Armenian ev "also, and;" Latin ob "toward, against, in the way of;" Oscan op, Greek opi- "behind;" Hittite appizzis "younger;" Lithuanian ap- "about, near;" Old Church Slavonic ob "on"). Before unaspirated vowels, reduced to ep-; before aspirated vowels, eph-. A productive prefix in Greek; also used in modern scientific compounds (e.g. epicenter).

epi- in Medicine

epi- or ep-
pref.

  1. On; upon: epineural.

  2. Over; above: epibasal.

  3. Around: epicystitis.

  4. Close to; near: epimer.

  5. Besides: epiphenomenon.

  6. After: epigenesis.