■ ordinal number
1》 constituting number nine in a sequence; 9th.
2》 ( a ~/one ~ ) each of nine equal parts into which something is or may be divided.
3》 Music an interval spanning nine consecutive notes in a diatonic scale.
↘the note which is higher by this interval than the tonic of a diatonic scale or root of a chord.
Derivatives
~ly adverb