a. A punctuation mark ( : ) used after a word introducing a quotation, explanation, example, or series and often after the salutation of a business letter.

b. The sign ( : ) used between numbers or groups of numbers in expressions of time (2:30 AM) and ratios (1:2).

a. A section of a metrical period in quantitative verse, consisting of two to six feet and in Latin verse having one principal accent.

b. An analogous unit or division of classical Greek or Latin prose.