1932, noun and verb, American English, apparently imitative. The transitive sense of the verb is first recorded 1940. Related: Burped; burping. Burp gun attested from 1945.
Noisy expulsion of gas from the stomach through the mouth. v. burped, burp·ing, burps
To expel gas from the stomach through the mouth.
To cause a baby to expel gas from the stomach, as by patting the back after feeding.
A belch, esp a gentle one