queer (adj.) Look up queer at Dictionary.com
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.
queer (v.) Look up queer at Dictionary.com
"to spoil, ruin," 1812, from queer (adj.). Related: Queered; queering. Earlier it meant "to puzzle, ridicule, cheat" (1790). To queer the pitch (1846) is in reference to the patter of a tradesman or showman (cf. sales pitch).