fifty

noun

fif·​ty ˈfif-tē 

plural fifties

1

: a number equal to five times 10 see Table of Numbers

2

fifties plural : the numbers 50 to 59

specifically : the years 50 to 59 in a lifetime or century

3

: a 50-dollar bill

fiftieth

ˈfif-tē-əth 

adjective or noun

fifty adjective

fifty pronoun, plural in construction

fiftyish

ˈfif-tē-ish 

adjective

Examples of fifty in a Sentence

She is in her fifties.

The bill for dinner came to $43, and she gave him a fifty.

Recent Examples on the Web

His overseas average in New Zealand, South Africa, Australia and England comes to just under 26 with two fifties in 11 Tests. —Tim Ellis, Forbes.com, 19 June 2025

Carol Sutton Lewis: In the late fifties, scientists at the Atomic Energy Commission were finding new information about a radioactive isotope called Strontium 90. —Carol Sutton Lewis, Scientific American, 18 June 2025

Another reporter told the story of how her father, back in the fifties, tinkered with his Oldsmobile in a way that it could be turned on by dialing a rotary telephone. —Frederick Dreier, Outside Online, 15 June 2025

Brainard grew up in Tulsa, Oklahoma, in the nineteen-forties and fifties, a world away from the capitals of literary and artistic production. —David S. Wallace, The New Yorker, 19 Mar. 2025

Word History

Etymology

Middle English, from fifty, adjective, from Old English fīftig, from fīftig, noun, group of 50, from fīf five + -tig group of ten; akin to tīen ten

First Known Use

before the 12th century, in the meaning defined at sense 1

Phrases Containing fifty

• fifty-fifty

Rhymes for fifty

• nifty
• shifty
• thrifty
• unthrifty

Kids Definition

fifty

noun

fif·​ty ˈfif-tē 

plural fifties

: a number equal to five times 10 see number

fiftieth

-tē-əth 

adjective or noun

fifty adjective or pronoun