Yesterday I saw a false etymology promoting an anti-trans agenda: the claim that the "cis-" in "cisgender" is related to words like "scissors" and "genocide." The latter two derive from the Latin verb "caedere," to cut or kill with a sword. The transphobe was claiming that the word "cisgender" expresses a transgender desire to murder everyone who isn't trans, i.e., a gender that is to be killed. That is obviously made up. The origin of the word "cisgender" is on the Wikipedia article for that word. If you wanted to say "gender must be slain" in Latin, it would be "genus caesum est," I believe. Funny thing is, I believe I did use the false etymology in my novel, as wordplay on "decide," "scissors," etc., having to do with cutting off options in the past and moving forward -- not to say that non-trans people should be cut down. And my novel is fiction, told by a fictional narrator.