More words from the Dictionary of Obscenity and Taboo:

UNMENTIONABLES [..] Between 1790 and the middle of the nineteenth century, by which time they had become established as acceptable, trousers were given a succession of silly and evasive names. As well as unmentionables, they were called inexpressibles, indescribables, unspeakables, ineffables, unexplicables, unwhisperables, innomonables, unutterables and unthinkables.

NUNNERY. A brothel. The term is not as popular now as it was in Elizabethan times when nuns had more dubious reputations than they do now. When Hamlet says to Ophelia “Get thee to a nunnery” it is clear from the context that he is using the word in this sense.

RIDE [..] Riding St. George is an old term for sexual intercourse with the woman sitting on top of the man. It was commonly believed in earlier centuries that a boy conceived in such circumstances was likely to grow up to become a bishop.

BITCH [..] There is a long history in English of words for women being devalued and becoming offensive. This systematic denigration of women is reflected, for example, in the history of words such as hussy, nymph, mistress, tart and whore. Why this should happen is something of a mystery, but whatever the reason the language is already littered by dozens, even hundreds, of such devalued words.

ONANISM [..] Knowing the above passage [Genesis 38: 8-10], a number of parrot owners (including Dorothy Parker) called their birds Onan because, like their Biblical namesake, they are given to spilling their seed on the ground.