etymonline.com gives:

oaf
1610 (implied in oafish), also auf (1621), "a changeling; a foolish child left by the fairies" [Johnson], from a Scand. source, cf. Norw. alfr "silly person," in O.N., "elf" (see elf). Hence, "a misbegotten, deformed idiot." Until recently, some dictionaries still gave the plural as oaves.

I have never heard it used any other way, though it's likely an acronym for something!

welcome, shalini!


formerly known as etaoin...