Queer

(dated) Weird, odd or different; whimsical. [from 16th c.]
(Britain, informal, dated) Slightly unwell (mainly in to feel queer). [from 18th c.]
(colloquial, sometimes derogatory) Homosexual. [from 19th c.]
(colloquial, sometimes derogatory) Not heterosexual: homosexual, bisexual, asexual, etc.
(broadly) Pertaining to sexual behavior or identity which does not conform to conventional heterosexual norms, assumptions etc. [from 20th c.]

Usage notes

Queer, in the sense of "gay" or "non-heterosexual", has gone in and out of use as a pejorative and as a self-identifier a number of times:[1] it began to be used to describe gay people in the late 1800s (e.g. in an 1894 letter by John Sholto Douglas),[2][3] and became more widespread in the US and became used as a self-identifier by American gay men by the 1910s, continuing into the 1950s, though by the 1940s younger ones considered it pejorative and preferred gay, which had been in used since the 1930s, and had come by the 1950s to encompass the whole LGBT community.[1][4] Queer began to be reclaimed as a neutral or positive descriptor by the 1980s,[5] at first most prominently by those who wanted to distinguish themselves from gay-identified people they felt had become too conservative and assimilationist.[6] Some other people oppose the term as being still pejorative, or too radical, too informal, or too technical.[7][8] The pejorative applied mainly to those assigned male at birth who were perceived as homosexual or effeminate; the reclaimed term is used by people of any sex or gender.[9] (Compare genderqueer, an umbrella term for noncisgender and non-binary — nonmale, nonfemale — gender identities.)