1825, "to strike with the head or horns" (of a goat or calf); perhaps an alteration of butt (v.) with a goat in mind, or a survival from Middle English bounten "to leap back, return" (early 15c., perhaps from a variant of Old French bondir; see bound (v.2)). As a baseball term from 1889. Also compare punt (v.). Related: Bunted; bunting.
1767, "a push with the head or horns" (of a goat or calf); see bunt (v.). Baseball sense "stop the ball with the bat without swinging the bat" is from 1889.