noun Um·bri·el \ˈəm-brē-ˌel\

Definition of Umbriel


  1. :  the third largest satellite of Uranus with a diameter of approximately 730 miles (1170 km) Earlier this year, Buratti and her co-workers reported other evidence suggesting that Umbriel might be a Uranian oddity. Analyzing photographs taken through various color filters by the Voyager 2 spacecraft, they found that the ratio of green light to violet light varies widely over Umbriel's surface. — Science News, 16 Nov. 1991

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First Known Use of umbriel


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a rounded knoll or a ridge of ice

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