It can mean anything you want it to mean. Ex: happiness, praise, anything, etc.
Person 1: "I just got a 100 on my last test!"
Person 2: "Dude, that's so jia."
Person 1: "So, what's up?"
Person 2: "I'm feeling jia today."
Person 1: "Jia! I just fell down the stairs!"
Person 2: "Are you jia?"
Person 1: "I hate my teacher. She's always yelling at me."
Person 2: "I know what you mean. She can be such a jia sometimes."
Person 1: "Have a jia summer! :)"
Jia means hi, and bye in the english langauge. Similiar to Shalom (computor inspired: Hia & Bia)
Jia Tim, this is my best friend; Bob.
Slang for yes, yeah, etc.
Q: Hey N-Dub you wanna hit up some b-ball?
A : Jia.