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

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

3. (n.) The quotient of a unit divided by twelve; one of twelve equal parts of one whole.

4. (n.) The next in order after the eleventh.

5. (n.) An interval comprising an octave and a fifth.

English horn Pandean pipe aulos basset horn basset oboe block flute bombard bourdon cello claribel clarinet clarion concert flute contrabassoon contrafagotto cornet cornopean cromorna cromorne cymbel diapason double bassoon double reed dulciana fife fipple flute flageolet flute flute stop foundation stop fourniture gamba gedeckt gemshorn harmonic flute hautboy heckelphone hornpipe hybrid stop koppel flute larigot licorice stick melodia mixture musette mutation stop nazard oaten reed oboe oboe da caccia ocarina octave organ stop panpipe penny-whistle piccolo pipe plein jeu pommer posaune principal quint quintaten rank ranket recorder reed reed instrument reed stop register rohr flute sax saxophone sesquialtera shawm single reed single-reed instrument sonorophone spitz flute stop stopped diapason stopped flute string diapason string stop sweet potato syrinx tabor pipe tenoroon tierce tin-whistle tremolo trombone trumpet twelfth unda maris vibrato viola voix celeste vox angelica vox humana whistle woods woodwind woodwind choir woodwind instrument