4B

1. A radical feminist movement originating in South Korea whose tenets are: no sex with men, no giving birth, no dating men, and no marriage with men.

   Ever since the election, there have been endless headlines about US women emulating South Korea’s fringe 4B movement[.]

   2024 November 16, Arwa Mahdawi, “Are US women protesting against Trump by ‘swearing off sex with men’?”, in The Guardian, →ISSN, archived from the original on 03 Dec 2024

   1 more example

   The blowback and fear that 4B practitioners experience underscores their conviction that Korea is still a frightening place for women.

   2023 March 8, Anna Louie Sussman, “The women of South Korea's 4B movement aren't fighting the patriarchy — they're leaving it behind entirely.”, in The Cut, archived from the original on 06 Nov 2024

plural 4Bs

1. UKA grade of pencil with lead that makes darker marks than a pencil grade 3B but lighter marks than a pencil of grade 5B; a pencil with very soft lead.