belch v.

Middle English bolken, from Old English bealcan "bring up wind from the stomach," also "swell, heave," of echoic origin (compare Dutch balken "to bray, shout"). It was extended to volcanoes, cannons, etc. 1570s. Related: Belched; belching. As a noun, "an act of belching," it is recorded from 1510s; also slang for "poor beer, malt liquor" (1706).