A combination of Friday and YAY!, typically to indicate excitement about said Friday; a portmanteau of "Friday" and "Yay".
Can also be applied to other
days of the week as such:
SaturYAY, SunYAY, TuesYAY, WednesYAY, and ThursYAY. There is no
MonYAY for obvious reasons.
Ann Marie - I've been waiting all week for this weekend. Happy FriYAY!
TJ - I've been waiting all week for FriYAY! I can't wait to
see ya.