To disregard, discredit, or disrespect.
Throwing dirt on someones name.
*Though used in
Canada, it is not only Western
Canadian slang. It is used commonly in the US ranging widely from NY to California since the late 70's (if not before that).
It is also a
popular word in the U.K.
Me: What happened to your eye?
John: Mikey and I got into a fight over Cecilia and he snuffed me in the face.
Me: Wait, what? Cecilia that girl you've been
dating?
John: Yep.
Me:
Wow and he was supposed to be your homeboy too... Damn you were dirted
hardcore.
John: I know he shitted on me, but paybacks a bitch.