Green’s Dictionary of Slang

ambisextrous adj.

(US) bisexual.

1904		V. Hunt Celebrity at Home 135: Such a contrast to the little anæmic, effete, ambisextrous (I hope I have got it right?) creatures that haunt Cinque Cento House.
1927		‘J.M. Hall’ Anecdota Americana I 45: A new word was coined for a certain actor whose inclinations were equally amorous for men as for women. One of his critics called him ‘ambisextrous.’.
1941		B. Schulberg What Makes Sammy Run? (1992) 54: Don’t give up girls [...] Haven’t you heard we’re ambi-sextrous.
1951		D.W. Cory Homosexual in America 112: The bisexual companion is ambisextrous.
1965		Guild Dict. Homosexual Terms 1: ambisextrous (adj.): Bisexual. (Rare.).
1972		B. Rodgers Queens’ Vernacular.
2001		www.queerbychoice.com 🌐 Ambidextrous? Ambigendered? Ambisextrous? Ambisexual?