Rigel Syllabification: (Ri·gel)Pronunciation: /ˈrījəl, -gəl/ AstronomyDefinition of Rigel the seventh brightest star in the sky, and the brightest in the constellation Orion. It is a blue supergiant nearly sixty thousand times as luminous as our sun. Origin:from Arabic rijl 'foot (of Orion)'Rigel in other Oxford dictionaries Definition of Rigel in the British & World English dictionary