oony Share definition Flag 1.Amazingly sexy girl. 2.Exceptionally good ass. 1. "Is she hott?" "Eh, Yeah, she's an OONY" 2."check out the oony on that chick." oony by posyluvsya May 23, 2005 0 0 Get merch Get the oony mug. Buy Now — $32.95 See more merch