A word that is used to expresses the complete and total awesomeness of a person/place/thing/idea.
This word is based on the artist Micky Yoochun of the Korean boyband DBSK, whose name 'Yoochun' ends with 'Chun' and is known for being (thinking he is) amazing/fantastic.
Girl #1: Did you see the way Junsu did that hip wiggle during 'Summer Dream'? :O
Girl #2: Yeah it was Chuntastic! :D