- gu
- to, ad, Irish go, gu, Old Irish co, cu, Welsh bw in bwy gilydd, to its fellow: *qos; Church Slavonic ku$$u, to; cf. Latin usque for *quos-que? (Bez.). Used adverbially in gu math, gu h-olc. Cf. Greek kas, kai, Sanskrit -ças.
Etymological dictionary of the Gaelic language. Alexander Gairm Publications. 1982.