RBI Share definition Flag RBI = Respectfully, boner inducing. The most polite way to compliment a person's hotness. Hey Shani, and I say this with love, your mom is RBI. She's a fantastic MILF. RBI by NastyN8Dawg July 20, 2021 0 0 Get merch Get the RBI mug. Buy Now — $32.95 See more merch