What is Byeah?
1.
An over-emphasis of the word "yeah"
Usually used in times of great happiness or for the funnies. The "No" of "BYEAH" is not "BNO" as that just sounds silly, the word is "BANANA"
Alisa to Dan
Alisa: Have fun at the gig last night?
Dan: BYEAH!
Alisa then punches Dan and elbows him in the side of the head
See
2.
To be absolutley positive about something.
"Is F1 a sport?"
Reply:
"Oh, BYeah!"