Twelfth \Twelfth\, a. [For twelft, OE. twelfte, AS. twelfta. See Twelve.]

1. Next in order after the eleventh; coming after eleven others; -- the ordinal of twelve.

2. Consisting, or being one of, twelve equal parts into which anything is divided.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Twelfth \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. (Mus.) An interval comprising an octave and a fifth.

Source: Webster's Revised Unabridged Dictionary (1913)