It's heroin, but in a black, sticky, TAR like substance. It's more common and easier to get in Mexico, hence its name.
"I like Mexican Tar better than smack because it's cheaper."
by Samantha July 01, 2003
1 more definition
The smell of cooking mexican tar evokes the same symptoms i expereince right before vomiting: hot, runny saliva, nausea, gagging. It is so grossly pungent & foul, but the addiction overpowers this truth & I continue.
by tabitha November 03, 2003