adj. causing great harm, or death, or something else real bad.
DAMN that was a pernicious fart.
by Emetic August 28, 2003
Get the pernicious mug.
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 8, 2011
Get the pernicious mug.
Having a harmful effect especially in a stubble or gradual way
The pernicious weed has spread all over the flower bed
by Banditzzi May 26, 2022
Get the pernicious mug.
adj: an all purpose word for something cool, hip, or awesome; or evil, twisted, and sick. Also functions well as a nickname.
Example of cool: Dude, Lord of the Rings: ROTK was SO pernicious!

Example of evil: Our algebra homework last night was PERNICIOUS! I didn't get any sleep!
by Niph April 24, 2004
Get the pernicious mug.
Freyalise set up us the bomb; Yawgmoth will pay for his treachery; Freyalise performed her pernicious deed.
by The Ravenclaw Seeker April 27, 2004
Get the pernicious mug.
Having love for somebody that causes harm towards you, knowing full well it’s bad for you. You want to stop, but you always come back.
“I don’t understand how she keeps coming back to that monster!”

“She’s feeling pernicious love.”
by Luca Simpson January 12, 2019
Get the Pernicious Love mug.
Help provided against the will of the provider and/or recipient
The grocery store bagger, in a fine display of pernicious assistance, quickly jammed my groceries into the paper bag, despite my saying "no thanks," as I finished paying the cashier. "It's my job, ma'am," his mouth said, as his eyes told me to get out of the way of the rest of the line.
by Pernicious Assistant November 10, 2021
Get the pernicious assistance mug.