Equuleus Syllabification: (E·quu·le·us)Pronunciation: /ēˈkwo͝olēəs/ AstronomyDefinition of Equuleus a small northern constellation (the Foal or Little Horse), perhaps representing the brother of Pegasus. It has no bright stars. (as genitive Equulei /ēˈkwo͝olēˌī/) used with a preceding letter or numeral to designate a star in this constellation:the star Delta EquuleiOrigin:LatinEquuleus in other Oxford dictionaries Definition of Equuleus in the British & World English dictionary