'Forty' definitions:

Definition of 'forty'

From: WordNet
adjective
Being ten more than thirty [syn: forty, 40, xl, twoscore]
noun
The cardinal number that is the product of ten and four [syn: forty, 40, XL]

Definition of 'Forty'

From: GCIDE
  • Forty \For"ty\, n.; pl. Forties (-t[i^]z).
  • 1. The sum of four tens; forty units or objects. [1913 Webster]
  • 2. A symbol expressing forty units; as, 40, or xl. [1913 Webster]

Definition of 'Forty'

From: GCIDE
  • Forty \For"ty\ (f[^o]r"t[y^]), a. [OE. forti, fourti, fowerti, AS. fe['o]wertig; fe['o]wer four + suff. -tig ten; akin to OS. fiwartig, fiartig, D. veertig, G. vierzig, Icel. fj["o]rut[imac]u, Sw. fyratio, Dan. fyrretyve, Goth. fidw[=o]r tigjus. See Four, and Ten, and cf. Fourteen.] Four times ten; thirty-nine and one more. [1913 Webster]