Green’s Dictionary of Slang

1. the head of the penis.

1966		Trimble 5000 Adult Sex Words and Phrases.
1973		B.S. Johnson All Bull 66: Walk flange in flange with me, / You are my destiny.

2. (orig. US) the vagina, esp. labia majora.

1985		‘Thommo’ Dict. Aus. Swearing & Sex Sayings n.p.: FLANGE — Vagina, referring mainly to the labia majora or outer lips.
1997–2002		Alt. Eng. Dict. 🌐 flange (noun, slang) Vagina.
1999		Roger’s Profanisaurus 3 in Viz 98 Oct. 13: flange 1. n. fish mitten. 2. n. coll. a group of baboons. 3. n. coll. Fanny; blart; tush.
2019		P. Baker Fabulosa 292/1: flange 1. a vagina.
2023		R. Milward Man-Eating Typewriter 32: ‘[W]e were raped repeatedly, oyster, flange, ripped dish’.