Variation of the phrase "long time no see!"
The difference is that it is only used when you have nothing else to say,
Verb/noun
Word used for fitness, physical eduction. Used also for "going to the gym" or "PE teacher". Origins of the word unknown.
"Yea im going gym today, do you want to Chan Chun with me?"
"Yes I am learning how the be a Chan Chun (PE teacher)"