1 Greek Mythology one of the Titans, wife of Cronus and mother of Zeus, Demeter, Poseidon, Hera, and Hades. Frightened of betrayal by their children, Cronus ate them; Rhea rescued Zeus from this fate by hiding him and giving Cronus a stone wrapped in blankets instead.

2 Astronomy a satellite of Saturn, the fourteenth closest to the planet, discovered by Cassini in 1672, and having a diameter of 951 miles (1,530 km).

a large flightless bird of South American grasslands, resembling a small ostrich, with grayish-brown plumage. • Family Rheidae: two species, Rhea americana and Pterocnemia pennata.