Wiktionary
b-word
n. 1 (context euphemistic English) The word ''bitch'', regarded as a vulgar or taboo word. 2 (context euphemistic English) Refers to any various taboo words beginning with ''b'', such as ''bastard'' or ''bugger''. 3 Any word beginning with ''b'' that is not normally taboo but is considered (often humorously) to be so in the given context.