Bah/bɑː/ Definition 1 of 3Pro Tip 1/3Emphasizing Disagreement Use 'bah' to strengthen your disagreement in an informal situation. Bah! That's absolutely not true. Pro Tip 2/3Expressing Disapproval Say 'bah' to show that you don't approve of something, almost like scoffing. Bah, such behavior is unacceptable! Pro Tip 3/3Rejecting Ideas Use 'bah' when you want to reject what someone else has said. Bah, I've heard enough of your excuses.