Pooner is a derogatory term for a trans man, especially one that doesn't pass or is believed to not put effort into passing. It is most commonly used by radical transmedicalists, but transphobic cis people have been known to use it as well.
History
The term originated on 4chan's /lgbt/ board on an unknown date. It comes from the word poontang, a slang term for the vagina.[1] A flag for those that reclaim the term was created by Tumblr user calloutgender on June 14th, 2024.[2]