When one is pretending to be knowledgeable of a subject that they know nothing about.
Knolegable person: Daft Punk's new song is just soooo lame. Don't you think
Crompastomper: Oh...erm...sure...I uh think that also. Cough...cough.
Knwledgable person to other knwledgeable friend: Oh he was soooooooo crompastompin'!