Short for chill session. Describes any amount of time spent with 1 or more people, although usually not large groups. A chillsesh is typically either last-minute or unofficially planned, and sometimes completely spontaneous. Because of this, a chillsesh can last anywhere from half an hour to several hours.
"Me and Jim were just walking around town and ran into Sarah, so we ended up having a chillsesh for a little while."
"Hey, you doin anything after school?"
"Nah."
"Chillsesh at my house?"
"Sounds good."
"So did you end up hanging out with her?"
"We didn't really hang out. We just had like a one-hour chillsesh, but then she had to go."
The next day after smoking marijuana the previous night, one tends to feel very chill and lazy about everything. A dumbover is the next step up, but sometimes you don't get a dumbover, just a chillover. If you have a dumbover, you usually have a chillover. If you have a chillover, you don't always have a dumbover.
-"I only smoked a bowl or two last night before bed, so I have a chillover today haha."
-"I didn't go to class today because I had a chillover, so I just played FarmVille instead."
The study and practice of Chill. Being opposed to chaos, the pure essence of chill is to be sought by studying what makes something or someone chill and practicing or experiencing this oneself.
"Listen to this chillout song, it makes me think about how someone is capable of producing something that so accurately captures the essence of chill. Still, I can't describe what it is."
- Yeah, I can't grasp it either, but luckily we can always practice chillosophy and approach it thoughtfully. Striving for chill.
"That's chill dude, you should be a chillosopher"
When you use minimal vocabulary and punctuation to try and look like you don't care about a subject on an internet forum. But you replied, so you probably do.