"secondary symptom," 1706, from epi- + phenomenon. Plural is epiphenomena. Related: Epiphenomenal.

before vowels reduced to ep-, before aspirated vowels eph-, 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," also "after," from PIE *epi, *opi "near, at, against" (source also of 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"). A productive prefix in Greek; also used in modern scientific compounds (such as epicenter).

"parasitic animal on the surface or in the skin of another," 1836, from epi- "on" + Greek zōon "animal" (from PIE root *gwei- "to live").

"adrenaline," 1883, from epi- "upon" + Greek nephros "kidney" (see nephron) + chemical suffix -ine (2). So called because the adrenal glands are on the kidneys.

"plant which grows upon another plant," 1827, from epi- "upon" + -phyte "plant." Related: Epiphytal; epiphytous (1816).

"nosebleed," 1793, medical Latin, as if from Greek *epistaxis, a false reading for epistagmos, from epi "upon" (see epi-) + stazein "to let fall in drops" (see stalactite).

1885 in seismology, "point on the earth's surface directly above the center or focus of an earthquake," from Modern Latin epicentrum (1879 in geological use); see epi- + center (n.). Related: Epicentral (1866).

"the checking of a discharge," medical Latin, from Greek epistasis "a stopping, stoppage, a halting," from epi "upon" (see epi-) + stasis "a stopping or standing," from PIE root *sta- "to stand, make or be firm."

1748, Modern Latin (Frederick Ruysch), from Greek epi "upon" (see epi-) + thēlē "teat, nipple" (from suffixed form of PIE root *dhe(i)- "to suck"). Related: Epithelial.

"marriage late in life," 1824, from Greek opse "late" (related to opiso "backward," opisthen "behind," from opi, a variant of epi "on it, at it;" see epi-) + -gamy "marriage."