Nine"teenth` (?), a. [Cf. AS. nigonteoa.]
1.
Following the eighteenth and preceding the twentieth; coming after eighteen others.
2.
Constituting or being one of nineteen equal parts into which anything is divided.
© Webster 1913.
Nine"teenth`, n.
1.
The quotient of a unit divided by nineteen; one of nineteen equal parts of anything.
2.
The next in order after the eighteenth.
3. Mus.
An interval of two octaves and a fifth.
© Webster 1913.