bah Share definition Flag something you say when u think something is ugly, or disgusting girl-hey do u like that guy over there? girl 2- BAhHHH eww hes ugly BAHHH 2) boy 1- he guess what im eating, a peanut and banana sandwich boy 2- BAHHH thats disgusting!! how could u eat that eww bahhh bah by Mnj2va May 16, 2006 Get the bah mug.