An Etymological Dictionary of Astronomy and Astrophysics

Firmly or closely fixed in place. → compact.

Etymology (EN): M.E. thight, from O.N. thettr “watertight, close in texture, solid” (cf. second element in O.E. metethiht “stout from eating;” M.H.G. dihte “dense, thick,” Ger. dicht “dense, tight,” O.H.G. gidigan, Ger. gediegen “genuine, solid, worthy”), from PIE base *tenk- “to become firm, curdle, thicken;” cf. Ir. techt “curdled, coagulated,” Lith. tankus “close, tight;” cognate with Pers. tang “tight,” as below.

Etymology (PE): Tang “tight; narrow, straight; tight,” also “horse girth, a strap for fastening a load” (Mid.Pers.
tang “tight, narrow”), tanjidan “to squeeze, press, pull together;”
cf. Skt. tanákti “draws together, contracts;” cognate with E. tight, as above; PIE base *tenk- “to become firm, curdle, thicken.”