epi- prefix variants: or ep- Trending Now: More Trending: lowlife kakistocracy slimeball salacious oligarch SEE ALL See What's Trending Now See More Trending Words What's Trending Now More Trending Words lowlife 'a person of low moral character' kakistocracy 'government by the worst people' slimeball 'a morally repulsive or odious person' salacious 'arousing or appealing to sexual desire' oligarch 'a member of a small group which exercises control of government' SEE ALL Time Traveler! Explore the year a word first appeared Definition of epi- 1 : upon epiphyte : besides epiphenomenon : attached to epididymis : over epicenter : outer epiblast : after epigenesis 2 a : chemical entity related to (such) another epimer b : chemical entity distinguished from (such) another by having a bridge connection epichlorohydrin See epi- defined for kids Origin and Etymology of epi- Latin, from Greek, from epi on, at, besides, after; akin to Old English eofot crime Seen and Heard What made you want to look up epi-? Please tell us where you read or heard it (including the quote, if possible). show hide