borrowed from Middle French & Latin; Middle French, borrowed from Latin mediocris "of medium size, moderate, middling, commonplace," perhaps originally "halfway to the top," from medius "middle, central" + -ocris, adjective derivative from the base of Old Latin ocris "rugged mountain," going back to Indo-European *hoḱ-r-i- "point, peak, edge" (whence also Umbrian ukar, ocar "citadel," Middle Irish ochair "edge, border," Welsh ochr, Greek ókris "top, point, corner"), derivative of *heḱ- "pointed"
adjective
of moderate or low quality, value, ability, or performance : ordinary, so-so