Boing Share definition Flag 1. Slang term for a well endowed women, in Japan 2. Being sexually aroused 1. Did you see that girl? Yeah she's such a boing. 2. Man, she definitely is . . . boing! Boing by SoHumhallelujah April 18, 2009 0 0 Get merch Get the Boing mug. Buy Now — $32.95 See more merch