forty

noun

for·​ty ˈfȯr-tē 

plural forties

1

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

2

forties plural : the numbers 40 to 49

specifically : the years 40 to 49 in a lifetime or century

3

: the third point scored by a side in a game of tennis

4

or 40 US, informal : a forty-ounce bottle or other container of an alcoholic beverage (such as beer or malt liquor)

Kelvin finished his forty in seven or eight long gulps. Tossed the bottle in the median carpeted with brown grass.

—Dave Byrne

… smoking weed and drinking 40s while her kids run loose.

—Jim Schutze

fortieth

ˈfȯr-tē-əth 

adjective or noun

forty adjective

forty pronoun, plural in construction

fortyish

ˈfȯr-tē-ish 

adjective

The Spelling of Forty: Usage Guide

Four is spelled with a u, as is fourteen. Forty, however, has no u, and neither does its close relation fortieth. There is no explanation for this inconsistency. In centuries past fourty was one of many spellings English users employed, but it had lost favor for reasons unknown by the end of the 18th century.

Examples of forty in a Sentence

The temperature outside is in the high forties.

She is in her forties.

Recent Examples on the Web

One client, a construction worker in his late forties, came to the company looking for income that did not depend on his body holding up. —Malana Vantyler, USA Today, 15 June 2026

But most of that decline had taken place in the years between the mid-forties and the early sixties. —Molly Fischer, New Yorker, 15 June 2026

The magic behind the work of Rick Dick, who is from Maremma, a rural area in Tuscany, and is in his forties, is the synergy between his skill for composing an image and his savviness for identifying the right moment. —José Criales-Unzueta, Vanity Fair, 10 June 2026

Sasheer Zamata is feeling good about entering her forties. —Lexi Lane, PEOPLE, 31 May 2026

Word History

Etymology

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

Phrases Containing forty

• forty-five
• forty-niner
• forty winks

Rhymes for forty

• corti
• rorty
• shorty
• sortie
• sporty
• warty
• pianoforte

Kids Definition

forty

noun

for·​ty ˈfȯrt-ē 

plural forties

: a number equal to four times 10 see number

fortieth

-ē-əth 

adjective or noun

forty adjective or pronoun

fortyish

-ē-ish 

adjective