bananaface Share definition Flag A bananaface is a guy who asks you to the prom, and then ditches you AFTER you bought the dress, to go with another girl. That Michael kid is a bananaface. He deserved to break his arm stepping out of the hot tub. bananaface by Miss Delaney May 13, 2005 0 0 Get merch Get the bananaface mug. Buy Now — $32.95 See more merch