Mimir. In Scandinavian mythology, the god of wisdom. Also god of the ocean, which is called "Mirmir's well," in which wit and wisdom lay hidden, and of which he drank every morning from the horn Gjallar. Odin once drank from this fountain, and by doing so became the wisest of gods and men; but he purchased the privilege and distinction at the cost of one eye, which Mimir exacted from him.