Cruspin Share definition Flag The booger hanging out of your nose when you're trying to chat up a lady. "Aw man, she was acting all weird and then I went to the toilet, looked in the mirror and I had a cuspin. No wonder she was repulsed!" Cruspin by Duncan Biscuits January 14, 2005 0 0 Get merch Get the Cruspin mug. Buy Now — $32.95 See more merch