Origin: before 900; Middle English; Old English sinu (nominative), sinuwe (genitive); cognate with Dutch zenuw,German Sehne,Old Norse sin; akin to Sanskrit snāva sinew
O.E. seonowe, oblique form of nom. sionu "sinew," from P.Gmc. *senawo (cf. O.S. sinewa, O.N. sina, O.Fris. sine, M.Du. senuwe, O.H.G. senawa, Ger. Sehne), from PIE base *sai- "to bend" (cf. Skt. snavah "sinew," Avestan snavar, Ir. sin "chain").