(1):

(a.) Constituting or being one of nineteen equal parts into which anything is divided.

(2):

(n.) The quotient of a unit divided by nineteen; one of nineteen equal parts of anything.

(3):

(a.) Following the eighteenth and preceding the twentieth; coming after eighteen others.

(4):

(n.) The next in order after the eighteenth.

(5):

(n.) An interval of two octaves and a fifth.