Belfast confetti

(slang) A brick or bricks thrown during a fight.

Irish confetti is a darkly humorous American and British slang phrase for bricks — specifically bricks thrown as weapons during a fight or riot. The term reflects an old ethnic stereotype associating Irish immigrants with street brawls and construction work. Its origins lie in the kind of derogatory ethnic humour that was common in the 19th and early 20th centuries. Today the phrase is considered offensive and is rarely used without awareness of its prejudiced roots. It's the kind of expression that turns up in historical texts or discussions of slang rather than current casual use.

(slang) Fluid ejaculated during orgasm.

(idiomatic, slang) A piece of machinery that is not worth more than its scrap value, often an old car.

(US, British) A loose thread of a naval or military uniform; also the loose end of any knot not tied properly.