a sarcastic way of saying something is good. (used to make fun of wiggers)
Wigger: Man check out ma sick ride yizzo!
Dude: YEAH MAN! ILL SICKNESS!
by Anonymous May 19, 2003
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when something is totally awesome & its not just ill (which means cool), but it is also sick (which means dope), therefore the coolness of the object just got boosted bc its twice as cool as an object simiply being ill.
jess: hey look @ those nikes....they are gold.

mikey: damn, those are ILL-SICK!!!
by ninjakari August 20, 2010
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the most illest happening on planet earth ever.
Oh shit son, that was ill sick nasty!

That new Apollo Sunshine CD is pretty ill sick nasty.

Could be used when the world is about to berak into peaces from a metor and superman, batman, and all the coolest super heroes distroy it together
by poophead2q3523432 February 12, 2006
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