A build up of fat underneath the bellybutton to where it protrudes further than you stomach A common slang word used to indicate happiness is lit. it conveys a sense of excitement or joy, often in relation to a fun event or good vibes. Perhaps you mean the french, faux pas, which translates as false step. it is pronounced similarly to what you wrote and does mean a mistake.
It could be referred to as a faux pas yes :) but, in most cases no, a faux pas is more of a 'no go' What is the slang word used to indicate happy
