Merriam-Webster's Collegiate® Dictionary, 11th Edition
QUEER
I. adjective
Etymology: origin unknown
Date: 1508
1. worthless , counterfeit , questionable , suspicious ,
2. differing in some odd way from what is usual or normal, b. eccentric , unconventional , mildly insane ; touched , absorbed or interested to an extreme or unreasonable degree ; obsessed, d. homosexual , gay 4b, not quite well, queerish adjective queerly adverb queerness noun
Usage: Over the past two decades, an important change has occurred in the use of queer in sense 2d. The older, strongly pejorative use has certainly not vanished, but a use by some gay people and some academics as a neutral or even positive term has established itself. This development is most noticeable in the adjective but is reflected in the corresponding noun as well. The newer use is sometimes taken to be offensive, especially by older gay men who fostered the acceptance of gay in these uses and still have a strong preference for it.
II. transitive verb
Date: circa 1812
to spoil the effect or success of , to put or get into an embarrassing or disadvantageous situation,
III. noun
Date: circa 1812
one that is queer, see: queer