1.  belching(n = noun.act) - the forceful expulsion of something from inside; "the belching of smoke from factory chimneys"
is a kind of ejection, expulsion, forcing out, projection

2.  belching(n = noun.act) belch, burp, burping, eructation - a reflex that expels gas noisily from the stomach through the mouth;
is a kind of ejection, expulsion, forcing out, projection, inborn reflex, innate reflex, instinctive reflex, physiological reaction, reflex, reflex action, reflex response, unconditioned reflex