A way of telling some one to calm down or to chill. Can also be used when something is personal and you want to say don't worry about it. Can be used to say you will relax.
You guys are making too much noise, you need to chill on it.
"So I saw you two together last night, what went down?"
"Chill on it"
I'm 'bout chill on it as soon as I get home.
1) To mull over in one's mind indefinitely without taking any sort of action. It is normally applied to difficult situations, when the moral or correct choice is obscured or nonexistent.
2) To hang out
1) Bob: Man, I don't know what to do about this...
Steve: Just chill on it, man.
2) Joe: What do y'all want to do?
Sam: Let's just chill on it.
Relax, the definition of the word is implied. The word is just catchy and a compacted version of chill out bro.