Comma \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 (Zo["o]l.), an American butterfly (Grapta comma), having a white comma-shaped marking on the under side of the wings.

Source: Webster's Revised Unabridged Dictionary (1913)