The description of the word you requested from the astronomical dictionary is given below.
A moon of 15 km diameter at about 17,983,000 km from the planet Saturn. The gravity at its surface is about 0.0003 times as strong as on Earth. The moon goes once around its planet in about 900.9 days. The moon was discovered in 2000. Also called SXXI (Saturn twenty-one). Its provisional designation was S/2000 S4.