(1):
(a.) Consisting, or being one of, twelve equal parts into which anything is divided.
(2):
(n.) The quotient of a unit divided by twelve; one of twelve equal parts of one whole.
(3):
(n.) The next in order after the eleventh.
(4):
(a.) Next in order after the eleventh; coming after eleven others; - the ordinal of twelve.
(5):
(n.) An interval comprising an octave and a fifth.