Zeus

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The principal god of the Greek pantheon, ruler of the heavens, and father of other gods and mortal heroes.

from The Century Dictionary.

• noun In Gr. Myth., the chief and master of the gods, the supreme deity, omnipresent and all-powerful, generally looked upon as the son of Kronos and Rhea, and held to have dethroned and succeeded his father
• noun [NL. (Linnæus, 1758).] In ichthyology, a genus of acanthopterygian fishes, typical of the family Zenidæ.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Gr. Myth.) The chief deity of the Greeks, and ruler of the upper world (cf. Hades). He was identified with Jupiter.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun A taxonomic genus within the family Zeidae — the John Dory and the Cape dory.
• proper noun A taxonomic genus within the family Rhytismataceae — a fungus discovered on Mount Olympus, with yellow disc-shaped fruiting bodies that grow in the decaying wood of Bosnian pine trees.
• proper noun Greek mythology Supreme ruler of all Greek gods, husband to Hera.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun type genus of the family Zeidae
• noun (Greek mythology) the supreme god of ancient Greek mythology; son of Rhea and Cronus whom he dethroned; husband and brother of Hera; brother of Poseidon and Hades; father of many gods; counterpart of Roman Jupiter