An unsightly glob of fat between the elbow and armpit which exists in lieu of a tricep. This jiggly extra addition to the anatomy is found exclusively on moms or grandmas. The Bingo-Wing is most noticeable when waving or yelling Bingo! at a church picnic.
Grandma: "Thanks for stopping by, we'll see you on your birthday!" (waves good bye)
Brother: "Did you see that Bingo-Wing? It almost knocked grandpas head off!"