A mild pejorative used to denote Radical feminists who exclude, display hatred and disgust for, and otherwise belittle
transgender women on the false and inaccurate claim that they are
men, because biological essentialism is actually okay with these "feminists", only as long as it's a cudgel used to shut up those dirty transes.
Internet TERFs may use talking points about how this is a "slur used to silence women and forced upon them by trans
people", however, it should be noted that TERFS themselves coined the term TERF, and only pivoted positions when the general public stopped agreeing with them. A slur is a loaded pejorative associated with immutable characteristics. You cannot change being black, gay, trans, etc. and thus, insults directed at someone for being any of these are defined as slurs. TERFism is simply a scientifically incorrect ideology in baldfaced opposition to the
American Psychiatric Association among others, and as you can change an ideology or outlook, it is not a slur. There are male TERFs, after all, ideologies aren't exclusive. And by TERF logic, things such as "nazi" "communist" and "
liberal" would be slurs as well.
British feminism is notorious for being overrun by ideological positions favored by TERFs, as it is favored by
white middle-aged cis, (usually) straight women who have
never dealt with discrimination in their lives.