Precisely that--a burp, usually small and noiseless but in which a small amount of stomach acid actually rises up the esophagous into the back of the throat, producing the the taste and aroma of vomit in one's mouth. Example: (erp) Oh, man, I just wet-burped. Man that tastes nasty! No kidding, Chris...I can smell it from here!
WET BURP
Meaning of WET BURP in English
Slang English vocab. Английский сленговый словарь. 2012