1. A self-important government official who holds several positions but performs little or no actual duties. The term comes from the character Pooh-Bah, Lord-High-Everything-Else, from The Mikado, a comic opera by W.S. Gilbert and Arthur Sullivan. Only that pooh-bah in the cabinet could hold so many titles and do so little.

2. The most important or powerful person in a group, organization, business, or movement (e.g., the boss, leader, etc.). I think it sounds like a great idea, but you'll have to ask the pooh-bah first.