The Collaborative International Dictionary of English v.0.48:
burp \burp\, burping \burping\n. a reflex that expels wind noisily from the stomach through the mouth. Syn: belch, belching, burping, eructation. [WordNet 1.5]WordNet (r) 3.0 (2006):
burping n 1: a reflex that expels gas noisily from the stomach through the mouth [syn: belch, belching, burp, burping, eructation]