Definitions
1.adjectiveWeird, odd or different; whimsical.
2.adjectiveSlightly unwell (mainly in "to feel queer").
3.adjectiveDrunk.
4.adjective(sometimes derogatory) Homosexual.
5.adjective(sometimes derogatory) Not heterosexual, or not cisgender: homosexual, bisexual, asexual, transgender, etc.
6.adjective(broadly) Pertaining to sexual or gender behaviour or identity which does not conform to conventional heterosexual or cisgender norms, assumptions etc."the queer community"
7.nounOne who queers something.