Amn't Share definition Flag Amn't is just another portmanteau. Just like isn't is the same as is not. In this case, amn't means am not. Rachel: "Usually I clean the house spotless, but I amn't today." Amn't by Ran(dum)words4u February 9, 2020 0 0 Get merch Get the Amn't mug. Buy Now — $32.95 See more merch