The prefix epi, from the Greek word meaning “at,” “close to,” “on,” “in addition to,” or “on the occasion of,” is at the root of a number of diverse words that pertain in some way to something associated with something else. This post lists and briefly defines many of these terms.
epicene (“in common”): having characteristics of both sexes (or neither), effeminate
epicenter (“on center”): the point of a planet’s surface above the focus of a seismic event
epicycle (“on circle”): a small circle moving on or around another circle
epidemic (“on people”): as an adjective, affecting a large number of people; as a noun, a widespread disease, although often generally in reference to a contagious or prevalent trend
epigone (“close upon birth”): originally, a lesser descendant of distinguished forebears; later, a disciple, follower, or imitator
epigram (“written on”): a brief, clever poem or saying, originally in verse form and often satirical
epigraph (“written on”): originally, an inscription on a statue or a structure; later, a brief but substantive statement at the front of a book or head of a chapter, or a motto
epilogue (“in addition to speech”): a conclusion, originally of a play
epiphany (“show on”): a manifestation or revelation, originally of Christ
episcopal (“look over”): pertaining to a bishop
episode (“in addition to entrance”): originally, commentary between songs as part of a Greek tragedy, later an experience or incident, and ultimately also a scene or a distinctive part of a narrative
epistemology (“standing over”): the study of, or a theory of, knowledge
epistle (“send to”): a letter
epistrophe (“turning about”): repetition of a word or phrase at the end of consecutive sentences or other syntactical units, or a comparative musical repetition
epitaph (“over tomb”): an inscription on a monument or tomb
epithalamium (“into bridal chamber”): a poem or song in honor of newlyweds
epithet (“place in addition”): a descriptive name for a person, place, or thing
epitome (“cut into”): originally, an abstract; later something typical or an embodiment of an ideal
Many medical and scientific terms with the epi- prefix, including epidermis (“on skin”) and epilepsy (“seize upon”), exist. Disguised related words include epexegesis (“additional explanation”), meaning “clarification of meaning”; ephemera (“on a day”), originally meaning “lasting for a day” and now referring to something transitory; epode (“after song”), meaning “a poem with a pattern of a long lines followed by a short line”; eponym (“on a name”), meaning “one whose name is applied to a place or a thing”; epoxy (“on oxygen”), a chemical compound used as a glue; and epoch (“on hold”), originally “a point marking the beginning of an era,” now more loosely synonymous with era itself.
Epicure and its derivatives, from the proper name Epicurus, are unrelated.