The story
Contracted initialism of B&D + D/s + S&M, meaning respectively bondage/discipline, dominance/submission, and sadism/masochism.
Etymology from Wiktionary, CC BY-SA 4.0.
BDSM
Today it means: A variety of often erotic practices involving bondage, discipline, sadomasochism, dominance and submission, and other related interpersonal dynamics. Full definition →