An adjective similar to cool referring to something that is either great or completely wrong.

S.i.c.k: backwards spells Kc-is! a term used by those who doing crazy ass shit n don’t give a fuck💯

1) Ill
2) Feeling nauseous/vomiting
3) Cool
4) Gross, Weird, Creepy.

Adjective.
Interesting, cool, new.

Can have various meanings,
In the U.S. it is usually used when something is cool and exciting.
In the UK it is used more to describe something not so pleasant, if something is gruesome and disgusting then it's sick.
The act of vomiting, feeling ill.

Said when you have no idea what others are talking about but feel the need to be a part of the conversation. May often lead to an Adeebify.