Eight"eenth` (?), a. [From Eighteen.]
1.
Next in order after the seventeenth.
2.
Consisting of one of eighteen equal parts or divisions of a thing.
© Webster 1913.
Eight"eenth`, n.
1.
The quotient of a unit divided by eighteen; one of eighteen equal parts or divisions.
2.
The eighth after the tenth.
© Webster 1913.