Webster's Revised Unabridged Dictionary · 1913

Eighteen

Eighteen (ā"tēn`) , adjective

[Anglo-Saxon eahtatȳne, eahtatēne. See Eight, and Ten, and compare Eighty.]

Eight and ten; as, eighteen pounds.

Eighteen , noun

1.
The number greater by a unit than seventeen; eighteen units or objects.
2.
A symbol denoting eighteen units, as 18 or xviii.