1. Talking about something or someone in a positive light, when in reality, the
words coming out of your mouth are pure fiction.
2. Talking about something you
don't know anything about while trying to present the illusion you are educated on the subject.
3. The act of saying absolutely ridiculous
shit.
example 1:
Joe: George Bush was the best president the United States ever had!
Jack: Imma punch you in your dumb
face if you don't stop that mouthassjackery.
example 2:
Vince Offer for the SlapChop:
... This thing, this tuna looks boring. Stop having a boring tuna, stop having a boring life. Add this tuna putting it in like this now you’re going to have a nice, tuna,
salad. Look at this you’re gonna have an exciting life now.
TV Viewer: LOL - good
ole'
Vince ... He is the master of mouthassjackery.