pass gas
To be flatulent; to fart. Someone passed gas right in the middle of Grandpa's story, and the whole table burst into laughter. If you can't avoid passing gas in the car, then at least have the courtesy to open the windows!
pass gas
Euph. to release intestinal gas through the anus. Someone on the bus had passed gas. It smelled awful. Something I ate at lunch made me pass gas all afternoon.