1. To make a broad statement based entirely on ignorance.
Statement could also be based on rumor, and/or negative or positive popular opinion.
2. To project your opinion of a particular subject as what everyone else's opinion should be.
Example 1. Person 1, "Brah, Circuit City is lametastic" Person 2,
"Do you have anything to base that on?" Person 1, "Well..
no." Person 2 "Dude, you're so clemtatious!"
Example 2. "Hey man, do you like Metallica's new stuff or old stuff
better?" Clemtatious guy says, "Dude, Metallica sucks"
To avoid being clemtatious, he could of said "Dude, I
don't like Metallica"