Synonyms for Eructation (same or very similar meaning)
WordNet sense 1 ((of volcanos) pouring out fumes of lava (or a deposit so formed)):
eruption, extravasationWordNet sense 2 (a reflex that expels wind noisily from the stomach through the mouth):
belch, burp, belching, burpingFrom the ODE community, based on WordNetadd/edit