before 900;Middle English,Old Englishmidd- (both an adj. and the initial element of a compound; modern spellings such as mid autumn are probably a reanalysis of mid- as an adj.); cognate with Old High Germanmitti,Old Norsemithr,Gothicmidjis,Old Irishmide,Latinmedius,Greekmésos,Sanskritmadhya middle, OCS mežda limit, border
O.E. mid, from P.Gmc. *medjaz (cf. O.N. miðr, O.S. middi, O.Fris. midde, O.H.G. mitti, Goth. midjis), from PIE *medhyo- (cf. Skt. madhyah, Gk. mesos, L. medius "middle;" see medial). Now surviving only as a prefix (midair, midstream, etc.); use as a preposition is often aphetic use of amid (cf. midshipman).