Can' cer (?), n. [L. cancer, cancri, crab, ulcer, a sign of the zodiac; akin to Gr. , Skr. karkaa crab, and prob. Skr. karkara h
ard, the crab being named from its hard shell. Cf. Canner, Chancre.] 1. (Zoöl.) A genus of decapod Crustacea, including some of the most common shore crabs of Europe and North America, as the rock crab, Jonah crab, etc. See Crab.