as

as c.1200, worn-down form of O.E. alswa "quite so" (see ALSO (Cf. also)), fully established by c.1400. Equivalent to so; any distinction in use is purely idiomatic. Related to Ger. als "as, than," from M.H.G. also. Phrase as well "just as much" is recorded from late 15c.; the phrase also can imply "as well as not," "as well as anything else." Interjection of incredulity as if! (i.e. "as if that really could happen") is attested from 1995.