Callo Share definition Flag One of Rallo descent who calls (sees) every bet placed in a Texas Hold em poker game, no matter what cards he holds in his hand. <i> Callo </i> called my bet with a 3 high! Callo by Ryan Weiss October 22, 2004 0 0 Get merch Get the Callo mug. Buy Now — $32.95 See more merch