Definition of twelfth

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