- preceded by seventeen others in a series; 18th
- designating any of the eighteen equal parts of something
Origin of eighteenthMiddle English eihtetenthe: see eighteen and -th
- the one following the seventeenth
- any one of the eighteen equal parts of something;
in the eighteenth place, rank, group, etc.
- The ordinal number matching the number 18 in a series.
- One of 18 equal parts.
- The ordinal form of the number eighteen.
- 18th, 18th; (in royal, papal and other names; for centuries) XVIII