noun for·ty \ˈfr-tē\

: the number 40

forties : the numbers ranging from 40 to 49

: a set of years ending in digits ranging from 40 to 49

plural forties

Full Definition of FORTY

— see number table
plural :  the numbers 40 to 49; specifically :  the years 40 to 49 in a lifetime or century
:  the third point scored by a side in a game of tennis
for·ti·eth \ˈfr-tē-əth\ adjective or noun
forty adjective
forty pronoun, plural in construction
for·ty·ish \-tē-ish\ adjective

Examples of FORTY

  1. The temperature outside is in the high forties.
  2. She is in her forties.

Origin of FORTY

Middle English fourty, adjective, from Old English fēowertig, from fēowertig group of 40, from fēower four + -tig group of 10; akin to Old English tīen ten
First Known Use: before 12th century

Other Number-Related Terms

jubilee, myriad, quarantine, score, twain

Rhymes with FORTY

FORTY Defined for Kids


adjective for·ty \ˈfr-tē\

Definition of FORTY for Kids

:  being four times ten



Definition of FORTY for Kids

:  four times ten :  40
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