Top Definition
adj. causing great harm, or death, or something else real bad.
DAMN that was a pernicious fart.
by Emetic August 28, 2003

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Soft and offensive. Just like you.

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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 07, 2011

The Urban Dictionary Mug

Lotsa space for your liquids.

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Lotsa space for your liquids.

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The Urban Dictionary Mug

Your favorite word on a white mug.

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The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

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The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

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The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

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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

The Urban Dictionary Mug

Lotsa space for your liquids.

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The Urban Dictionary Mug

Lotsa space for your liquids.

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The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

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The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

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The best type of deed!
Freyalise set up us the bomb; Yawgmoth will pay for his treachery; Freyalise performed her pernicious deed.
by The Ravenclaw Seeker April 27, 2004

The Urban Dictionary Mug

Lotsa space for your liquids.

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The Urban Dictionary Mug

Lotsa space for your liquids.

Buy the mug

The Urban Dictionary Mug

Your favorite word on a white mug.

Create a mug

The Urban Dictionary Mug

One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.

Buy the mug

The Urban Dictionary T-Shirt

Soft and offensive. Just like you.

Buy the t-shirt

The Urban Dictionary T-Shirt

Smooth, soft, slim fit American Apparel shirt. Custom printed. 100% fine jersey cotton, except for heather grey (90% cotton).

Buy the t-shirt