Any of various slow-moving, microscopic invertebrates of the phylum Tardigrada that have four body segments, eight legs, and a chitinous cuticle, inhabit aquatic or moist terrestrial environments, and can withstand extreme temperatures. Also called water bear.
1. Of or belonging to the Tardigrada.
2. Slow in action; slow-moving.
[New Latin Tardigrada, phylum name, from neuter pl. of Latin tardigradus, slow-moving : tardus, slow + -gradus, walking, moving (from gradī, to go; see TRANSGRESS). Adj., sense 2, from Latin tardigradus.]
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