comma

1. (typography) The punctuation mark ⟨,⟩ used to indicate a set of parts of a sentence or between elements of a list.Examples: "No points were used by the ancient printers, excepting the colon and the period; but, after some time, a short oblique stroke, called a virgil, was introduced, which answered to the modern comma. In the fifteenth century this punctuation was improved by the famous Aldus Manutius with the typographical art in general; when he gave a better shape to the comma, added the semicolon, and assigned to the former points more proper places."Synonyms: scratch comma, virgule, virgula, come, comma-point

2. (Romanian typography) A similar-looking subscript diacritical mark.Romanian

3. (entomology) Any of various nymphalid butterflies of the genus Polygonia, having a comma-shaped white mark on the underwings, especially Polygonia c-album and Polygonia c-aureum of North Africa, Europe, and Asia.Examples: "Commas (Polygonia comma) and Question Marks (Polygonia interrogationis) occur from the Gulf Coast to Canada and west to the Rockies. [...] Question Marks and Commas are handsome butterflies with burnt orange and black markings. [...] On the underside of each hind wing of the Comma is a small, distinctive silver hook that resembles a comma."; "Other members of this genus that are frequently encountered in the park are the eastern comma (P. comma) and question mark (P. interrogationis)."

4. (music) A difference in the calculation of nearly identical intervals by different ways.

5. (genetics) A delimiting marker between items in a genetic sequence.

6. (rhetoric) In Ancient Greek rhetoric, a short clause, something less than a colon, originally denoted by comma marks. In antiquity it was defined as a combination of words having no more than eight syllables in all. It was later applied to longer phrases, e.g. the Johannine comma.rhetoric