pernicious

Describes something that really messes you up. Most of the time you can't tell at the beginning but before you know it, it really fucks you up.
Person 1: It ain't worth it bro, you know Prozac is pernicious. Don't take it.

Person 2: Too late, I can't get off of it now.

Person 1: Damn, I hope you don't get erectile dysfunction like that other kid.

Person 2: Too late for that too...
by Moses D. October 08, 2011
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