Origin: before 900; Middle English, variant of Middle English thider,Old English, alteration of thæder (i from hiderhither); akin to Old Norse thathra there, Gothic thathro thence, Sanskrit tátra there, thither
O.E. þider "to or toward that place," altered (by infl. of its opposite hider) of earlier þæder "to that place," from P.Gmc. *thadra- (cf. O.N. þaðra "there"), from *tha (see that) + PIE suffix denoting motion toward (cf. Goth. -dre, Skt. -tra).