I've never seen it used as a verb. As for its use as an adjective, no, it is not obsolete but nor it is used in everyday conversation to mean 'strange' as it was in the past. The reason is that at some point the word started to be used as a homophobic slur towards gay people. Nowadays, the word seems to have been 'reclaimed' of sorts by people in the LBGT community and you may hear certain people refer to themselves as 'queer' to refer to their sexual identity.

Queer is not used much anymore because it has become a term used to refer to gay people in a rude manner usually. LGBTQ (lesbian, gay, bi, trans, queer) Hope this helped.

I'm old enough to have heard it as a verb... "to queer the deal," which we would now probably phrase as "to be a deal-breaker." "Queer" used to be a very ordinary everyday word for "strange" or "odd" or "unusual." Around the late 1950s it began to be understood to mean "homosexual" and it stopped being used with other meanings. Much the same thing has happened to the word "gay." If something was written before about 1960, you can interpret "queer" as meaning "strange." But don't try to use it that way. Perhaps some people are familiar with the great Rodgers & Hammerstein musical "comedy" (more of musical tragedy), "Carousel?" It was written in 1945. It contains a song with a lyric in which "queer" means simply "strange:" Carrie: You're a queer one, Julie Jordan, You are quieter and deeper than a well And you never tell me nuthin'! Julie: There's nuthin' that I care to choose to tell. In "Alice's Adventures in Wonderland," Alice says: 'I wish I hadn't cried so much!' said Alice, 'I shall be punished for it now, I suppose, by being drowned in my own tears! That will be a queer thing, to be sure! However, everything is queer to-day.'''

'Queer' as a verb is very rarely used. It's an archaic use that most native speakers have never heard of. You can forget about 'queer' as a verb. 'Queer' is a very normal adjective, meaning 'odd'. At some point it became a term to refer to gay men - He's queer or He's a queer (noun). This term is not especially derogatory, though, and at times it has even been used within the gay community. Nevertheless, this other meaning is so well known that people tend to avoid it, and use 'odd' 'strange' 'peculiar' or 'funny' instead. There are plenty of alternative words, so sometimes it's easier to choose one of these rather than have people laughing and making 'double entendre' jokes about gay people.

Queer isn't a word that is typically used in everyday speech. You'll often see it in old movies, books, etc, to mean "odd/silly/strange", but nobody really uses it like that anymore. Nowadays its used mostly when referring to people who do not follow typical gender/sexuality norms. Ex: Oh, you're going to the LGBTQ+ meeting? Are you gay? Nah, I'm queer. Sometimes people use "queer" as an insult, just as someone may use "gay" as an insult, but I know plenty of people that refer to themselves as "queer" in a perfectly normal, respectful way.