Back-formation from prissy (analyzed as priss + -y (“(manner)”)); noun attested 1923.
Meanings
(informal) A prissy person
Robin: Have you ever been in love? / Steve: Yep. Nancy Wheeler. First semester, senior year. / Robin: Oh my God. She's such a priss. 2019, Stranger Things, season 3, episode 7, spoken by Steve Harrington and Robin Buckley (Joe Keery and Maya Hawke):
uk мані́житися (to behave in a prissy manner) · ru жема́нничать (to behave in a prissy manner) · uk мані́ритися (to behave in a prissy manner) · fi tärkeillä (to behave in a prissy manner)