The description of the word you requested from the astronomical dictionary is given below.
A moon of 162 km diameter at about 86,000 km from the planet Uranus. The gravity at its surface is about 0.0030 times as strong as on Earth. The moon goes once around its planet in about 18.3 hours. The moon was discovered in 1985. Also called UXV (Uranus fifteen). Its provisional designation was S/1985 U1.