Epi-
Epi-
[Greek 'epi` on, upon, to; akin to Sanskrit api besides, and prob. to Latin ob to, before, on account of, and perh. to English of, off.]
A prefix, meaning upon, beside, among, on the outside, above, over. It becomes ep-before a vowel, as in epoch, and eph-before a Greek aspirate, as in ephemeral.