sumpin Share definition Flag Bitched version of the word something. It is most commonly used in the phrase "humpin' sumpin' new" which translates to "engaging in kinky sex." Nice ass, Fido, I'm glad to be humpin' sumpin' new. sumpin by GuidoPosse69 February 2, 2005 0 0 Get merch Get the sumpin mug. Buy Now — $32.95 See more merch