Twelfth /(twĕlfth)/

Twelfth

a.
  1. Next in order after the eleventh; coming after eleven others; -- the ordinal of twelve.
  2. Constituting, or being one of, twelve equal parts into which anything is divided.

Twelfth

n.
  1. The quotient of a unit divided by twelve; one of twelve equal parts of one whole.
  2. The next in order after the eleventh.
  3. An interval comprising an octave and a fifth. (Mus.)