meathammer Share definition Flag a man's 5th appendage, usually located above the testicle region. i slapped my meathammer on some bitches cottage cheese ass and left a mushroom brooze. She refuses to speak to me after the said event. meathammer by kozimoto June 19, 2008 0 0 Get merch Get the meathammer mug. Buy Now — $32.95 See more merch