A social blunder, usually verbal.
"Them Jews man, what a bunch of big nosed cry babies, always banging on about the holocaust. It happened like a century ago, just get over it! Don't get me started on Israel! By the way, what's your name?"
A gaffe is when a politician accidentally tells the truth.
Joe Biden aka gaffe-o-matic: "What am I going to tell the President when I tell him his teleprompter is broken? WHAT WILL HE DO THEN?
A burp one does prior to or during the process of throwing up, vomiting, being sick, puking, blowing chunks or similar.
"You know you're gonna throw up whenever you gaffe."
"After half an hour with her head in the toilet, she surfaced briefly for a hearty gaffe."
Matt - "I wasn't that drunk..."
Tim - "Man, you gaffed in my face."