What are some great underused slang words or expressions?

To add a little to Dan Smith's answer; having served in the Royal Navy myself I can add a couple of related 'Jack Speak' terms in relation to 'getting the wets in''. read more

Below is a list of common American slang word and phrases that our English-speaking comrades in Great Britain might have trouble wrapping their heads around. American Slang Words and Phrases: Bail — Intransitive verb for leaving abruptly. read more

Tmesis — 144k — The separation of parts of a compound word by an intervening word or words (e.g. every-fucking-thing). Concinnity — 147k — The skillful and harmonious arrangement or fitting together of the different parts of something. read more