1590s, "a Norwegian," from obsolete Dutch Noorsch (adj.) "Norwegian," from noordsch "northern, nordic," from noord "north" (see north). Also in some cases borrowed from cognate Danish or Norwegian norsk. As a language, from 1680s. Old Norse attested from 1844. An Old English word for "a Norwegian" was Norðman. As an adjective from 1768.
In Old French, Norois as a noun meant "a Norse, Norseman," also "action worth of a man from the North (i.e. usually considered as deceitful)" [Hindley, et. al.]; as an adjective it meant "northern, Norse, Norwegian," also "proud, fierce, fiery, strong."