'Eighteen' definitions:

Definition of 'eighteen'

(from WordNet)
adjective
Being one more than seventeen [syn: eighteen, 18, xviii]
noun
The cardinal number that is the sum of seventeen and one [syn: eighteen, 18, XVIII]

Definition of 'Eighteen'

From: GCIDE
  • Eighteen \Eight"een`\ ([=a]"t[=e]n`), a. [AS. eahtat[=y]ne, eahtat[=e]ne. See Eight, and Ten, and cf. Eighty.] Eight and ten; as, eighteen pounds. [1913 Webster]

Definition of 'Eighteen'

From: GCIDE
  • Eighteen \Eight"een`\, n.
  • 1. The number greater by a unit than seventeen; eighteen units or objects. [1913 Webster]
  • 2. A symbol denoting eighteen units, as 18 or xviii. [1913 Webster]