the sign (:) used to mark a major division in a sentence, to indicate that what follows is an elaboration, summation, implication, etc., of what precedes; or to separate groups of numbers referring to different things, as hours from minutes in 5:30; or the members of a ratio or proportion, as in 1 : 2 : : 3 : 6.
one of the members or sections of a rhythmical period, consisting of a sequence of from two to six feet united under a principal ictus or beat.