The term gassed when associated with someone else, can mean they are full of sh*t.

On the other hand, the term gassing can be used in the context where someone states that whatever the other person is saying is a total lie.
Person 1: 'You are so Gassed'

Or

Person 1: 'Quit Gassing'

Person 2: I'm serious!

Gassed, Gassing.
by Crabroast22 January 20, 2011
Get the Gassed, Gassing mug.