When someone uses a trans person's dead pronouns, as opposed to their correctly gender-confirming pronouns. (Compound word on the style of DEADname+proNOUN. Similar to how ANTIbody GENerator becomes antigen)
shit, my boomer dad just deadnouned me yesterday.
"Oh, she just came over yesterday for tea" "oh, you mean 'they' - 'she' is their deadnoun"