Rhea

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

• noun Greek Mythology The sister and wife of Cronus and the mother of Demeter, Hades, Hera, Hestia, Poseidon, and Zeus.
• noun A satellite of Saturn.

from The Century Dictionary.

• noun The ramie-plant or -fiber.
• noun In anc. myth., a daughter of Uranus and Ge, or Heaven and Earth, wife and sister of Kronos, and mother of various divinities.
• noun [NL.] In ornithology: The only genus of Rheidæ; the only American genus of living ratite birds; the only three-toed ostriches.
• noun [lowercase] An American ostrich.
• noun The fifth satellite of Saturn.

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

• noun (Bot.) The ramie or grass-cloth plant. See Grass-cloth plant, under grass.
• noun (Zoöl.) Any one of three species of large South American ostrichlike birds of the genera Rhea and Pterocnemia. Called also the American ostrich.

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

• proper noun Greek mythology A Titan, the daughter of Uranus and Gaia, the mother of Demeter, Hades, Hera, Hestia, Poseidon, and Zeus.
• proper noun astronomy One of the moons of Saturn.
• proper noun A female given name in occasional use.
• proper noun A taxonomic genus within the family Rheidae — the rheas.

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

• noun fertility goddess in ancient Greek mythology; wife of Cronus and mother of Zeus; identified with Roman Ops and Cybele of ancient Asia Minor
• noun larger of two tall fast-running flightless birds similar to ostriches but three-toed; found from Brazil to Patagonia
• noun smaller of two tall fast-running flightless birds similar to ostriches but three-toed; found from Peru to Strait of Magellan