eighteenth Meaning, Definition & Usage

  1. noun position 18 in a countable series of things
  2. adjective satellite coming next after the seventeenth in position
    18th.

WordNet

Eight"eenth` adjective
Etymology
From Eighteen.
Definitions
  1. Next in order after the seventeenth.
  2. Consisting of one of eighteen equal parts or divisions of a thing.
Eight"eenth` noun
Definitions
  1. The quotient of a unit divided by eighteen; one of eighteen equal parts or divisions.
  2. The eighth after the tenth.

Webster 1913