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Medical Term:


Pronunciation: ar-throp′ŏ-dă

Definition: A phylum of the Metazoa that includes the classes Crustacea (crabs, shrimp, crayfish, lobsters), Insecta, Arachnida (spiders, scorpions, mites, ticks), Chilopoda (centipedes), Diplopoda (millipedes), Merostomata (horseshoe crabs), and various other lesser known or extinct groups. Arthropoda forms the largest assemblage of living organisms, including 75% of all insects, of which more than a million species are known.

[arthro- + G. pous, foot]