n! Share definition Flag read as "n factorial". It describes the product of all numbers from 1 to n. 5! = 1 * 2 * 3 * 4 * 5 = 120 2! = 1 * 2 = 2 n! n! by Lived Ip February 12, 2006 0 0 Get merch Get the n! mug. Buy Now — $32.95 See more merch