fart moisture Share definition Flag Fart moisture is the result of water evaporating off a turtle head and condensing in one's undergarments/arse crack/trousers. Oh dear, oh dear... I'm stuck here with fart moisture... I had better have a poo, hadn't I? fart moisture by Agent 47 July 15, 2007 0 0 Get merch Get the fart moisture mug. Buy Now — $32.95 See more merch