Adir Hu (English: Mighty is He, Hebrew אדיר הוּא) is a hymn sung by Jews worldwide at the Passover Seder. It switches rapidly between saying the virtues of God in an alphabet format (Aleph, Bet, Gimel,...), and expressing hope that God will "rebuild the Holy Temple speedily." Most of the virtues of God are adjectives (for instance, Holy (Kadosh) is he); however, a few are nouns. (Lord is he).
Adir Hu is sung towards the end of the Seder. The traditional melody is a bouncy, major one. Other melodies, however, have been composed for the alphabetical song.