Com″ma (?), n. [L. comma part of a sentence, comma, Gr. � clause, fr. � to cut off. Cf. Capon.] 1. A character or point marking the smallest divisions of a sentence, written or printed.
2. (Mus.) A small interval (the difference between a major and minor half step), seldom used except by tuners.
Comma bacillus(Physiol.), a variety of bacillus shaped like a comma, found in the intestines of patients suffering from cholera. It is considered by some as having a special relation to the disease; — called also cholera bacillus. — Comma butterfly(Zoöl.), an American butterfly (Grapta comma), having a white comma-shaped marking on the under side of the wings.