just chillin has many meanings.
the most common are when an individual really isnt gettin into shit.usually replied back when tryna chill alone.
chillin can also refer to sittin down somewhere,blazin up,wit a lil kil or maybe some good up in the cup.shit maybe even both...yeah..
the other derivative of the word is used as a reply when an individual is smokin with others or is confronted about being high,or drunk,but is not fully gone yet...just chillin.
Essentially meaning 'I'm just saying', 'just casually' is most often placed at the end of a sentence, often preluded by an idea or statement that is commonly accepted as truth. As a result, it is most often used following an observation. 'Just casually' is a light phrase that connotates feelings of ease to others, as it often has the effect of putting less emphasis on the matter/issue at hand.