A celebratory exclamation, usually delivered with a
squeaky or
high-pitched intonation.
The last word--capowie--can never be spelled with a K. Ever. That would just be
silly.
Larry: Oh my
god!
Leslie: What is it, Larry?
Larry: I just got a new high score in Robot
Unicorn Attack!
Leslie: YEAHYEAHYEAH WOWIE CAPOWIE!