The description of the word you requested from the astronomical dictionary is given below.
A moon of 51 km diameter at about 59,200 km from the planet Uranus. The gravity at its surface is about 0.0010 times as strong as on Earth. The moon goes once around its planet in about 10.4 hours. The moon was discovered in 1986. Also called UVIII (Uranus eight). Its provisional designation was S/1986 U9.