CepheusPronunciation: /ˈsiːfɪəs/ AstronomyDefinition of Cepheus a constellation near the north celestial pole, with no very bright stars. (as genitive Cephei /ˈsiːfɪʌɪ/) used with preceding letter or numeral to designate a star in this constellation:the star Beta CepheiOrigin:from the name of a king of Ethiopia, the husband of CassiopeiaCepheus in other Oxford dictionaries Definition of Cepheus in the US English dictionary