Eructation

n. burping, belching; violent expulsion

Burping, also known as belching, ructus, or eructation is the release of gas from the digestive tract (mainly esophagus and stomach) through the mouth. It is often accompanied with a typical sound and sometimes an odor.
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Eructation /eruc·ta·tion/ belching; casting up wind from the stomach through the mouth. e·ruc·ta·tion n. The act or an instance of belching. [more]Eructation - Community and Resources

Noun
1. (of volcanos) pouring out fumes or lava (or a deposit so formed)
(synonym) eruption, extravasation
(hypernym) action, activity, activeness
(derivation) spew, spew out, eruct
(classification) vent, volcano
2. a reflex that expels wind noisily from the stomach through the mouth
(synonym) belch, belching, burp, burping
(hypernym) reflex, instinctive reflex, innate reflex, inborn reflex, unconditioned reflex, physiological reaction
(derivation) burp, bubble, belch, eruct

n. eructation