The description of the word you requested from the astronomical dictionary is given below.
A moon of 419 km diameter at about 117,650 km from the planet Neptune. The gravity at its surface is about 0.0078 times as strong as on Earth. The moon goes once around its planet in about 26.9 hours. The moon was discovered in 1989. Also called NVIII (Neptune eight). Its provisional designation was S/1989 N1.