Definition of Andromeda
1 Greek Mythology an Ethiopian princess whose mother Cassiopeia boasted that she herself (or, in some stories, her daughter) was more beautiful than the Nereids. In revenge, Poseidon sent a sea monster to ravage the country; to placate him, Andromeda was fastened to a rock and exposed to the monster, from which she was rescued by Perseus.
2 Astronomy a large northern constellation between Perseus and Pegasus, with few bright stars. It is chiefly notable for the Andromeda Galaxy (or Great Nebula of Andromeda), a conspicuous spiral galaxy probably twice as massive as our own and located 2 million light years away.
(as genitive Andromedae
/anˈdrämiˌdē/) used with a preceding letter or numeral to designate stars in this constellation:the star Gamma Andromedae