Definition of Cassiopeia
1 Greek Mythology the wife of Cepheus, king of Ethiopia, and mother of Andromeda. 2 Astronomy a constellation near the north celestial pole, recognizable by the conspicuous “W” pattern of its brightest stars.
(as genitive Cassiopeiae
/ˌkasēəˈpē-ē/) used with a preceding letter or numeral to designate a star in this constellation:the star Delta Cassiopeiae