- next after the eighth; being the ordinal number for nine.
- being one of nine equal parts.
- a ninth part, especially of one (1/9).
- the ninth member of a series.
- a tone distant from another tone by an interval of an octave and a second.
- the interval between such tones.
- harmonic combination of such tones.
- in the ninth place.
- (usually prenominal)
- coming after the eighth in counting order, position, time, etc; being the ordinal number of nine. Often written: 9th
- (as noun)he came on the ninth; ninth in line
- one of nine equal or nearly equal parts of an object, quantity, measurement, etc
- (as modifier)a ninth part
- the fraction equal to one divided by nine (1/9)
- an interval of one octave plus a second
- one of two notes constituting such an interval
- See ninth chord
- Also: ninthly after the eighth person, position, event, etc
- Also: ninthly as the ninth point: linking what follows to the previous statement
c.1300, modification (by influence of nine) of nigonðe, from Old English nigoða, nigend.