The description of the word you requested from the astronomical dictionary is given below.
A moon of 5 km diameter at about 23,280,000 km from the planet Jupiter. The gravity at its surface is about 0.0002 times as strong as on Earth. The moon goes once around its planet in about 725.5 days. The moon was discovered in 2000. Also called JXX (Jupiter twenty). Its provisional designation was S/2000 J9.