O.E. uncuð "unknown, uncertain, unfamiliar," from
un- (1) "not" + cuð "known, well-known," pp. of cunnan "to know" (see
can (v.)). Meaning "strange, crude, clumsy" is first recorded 1513. The compound (and the thing it describes) widespread
in IE languages, cf. L. ignorantem,, O.N. ukuðr, Goth. unkunþs, Skt. ajnatah, Armenian ancanaut', Gk. agnotos, O.Ir. ingnad "unknown."