Found 2 items, similar to pygidia.
English → English (WordNet) Definition: pygidia pygidia See pygidium
English → English (gcide) Definition: Pygidia Pygidium \Py*gid"i*um\, n.; pl. Pygidia. [NL., fr. Gr. ?, dim. of ? the rump.] (Zo["o]l.) The caudal plate of trilobites, crustacean, and certain insects. See Illust. of Limulus and Trilobite. [1913 Webster]