A small turd lingering within a huge fart. You don't know it is there. When you let it fly a gasturd can be propelled at a rate speed beyond that in which a bullet exits a gun.
When a gasturd hits the water, your ass gets soaked, similarly to sitting in the Splash Zone at the Shamu show.
A gasturd has the greatest 'size to impact' ratio of any object known to man.
A gasturd may easily be mistaken as a shart, so please remember a gasturd exists within a fart and is not a mistaken fart.
"Wholly shit, what was that. I thought it was only a fart, but it was a gasturd. It shattered the toiletbowl and I am soaked."
A turd propelled at a high rate of speed from your butthole by a fart.
"I shot out a gasturd and it made the pee-water splash all up on my butthole."