c.1500, "strange, peculiar, eccentric," from Scottish, perhaps from Low German (Brunswick dialect) queer "oblique, off-center," related to German quer "oblique, perverse, odd," from Old High German twerh "oblique," from PIE root *terkw- "to turn, twist, wind" (see thwart (adv.)).
Sense of "homosexual" first recorded 1922; the noun in this sense is 1935, from the adjective. Related: Queerly. Queer studies as an academic discipline attested from 1994.