tardigrada

WORDNET DICTIONARY

tardigrada(n = noun.animal) class tardigrada - in some classifications considered a separate phylum: microscopic arachnid-like invertebrates living in water or damp moss having 4 pairs of legs and instead of a mouth a pair of stylets or needlelike piercing organs connected with the pharynx;

is a member of arthropoda, phylum arthropoda

is a kind of class

tardigrada, n. pl. [NL. See Tardigrade, a.].

A tribe of edentates comprising the sloths. They are noted for the slowness of their movements when on the ground. See Sloth, 3. [1913 Webster]
An order of minute aquatic arachnids; -- called also bear animalcules, sloth animalcules, and water bears. [1913 Webster]