fourth

noun

ˈfȯrth 

plural fourths ˈfȯr(th)s 

1

: one that is number four in a series

I was the fourth to arrive.

They arrive on the fourth. [=the fourth day of the month]

see Table of Numbers

2

: one of four equal parts of something : quarter entry 1

Cut the cake into fourths.

a fourth of the population

3

a

: a musical interval (see interval sense 2) embracing four tones of the diatonic scale

b

: a tone at this interval

specifically : subdominant sense 1

c

: the harmonic combination of two tones a fourth apart

4

: the fourth forward gear or speed of a motor vehicle

shifted into fourth

5

the Fourth : July 4 observed as a legal holiday in the U.S. in commemoration of the adoption of the Declaration of Independence in 1776 : Fourth of July

watched fireworks on the Fourth

called also Independence Day

fourth adjective or adverb

the fourth edition of a book

the fourth tallest mountain

fourthly adverb

Fourthly, don't sing a whole opera through …

—Mark Twain

Examples of fourth in a Sentence

cut the cake into fourths

She drank a fourth of the bottle.

Recent Examples on the Web

As the stars weathered Friday's episode while down a cohost in the absence of Sunny Hostin, Behar singled out one-fourth of the panel at the top of the show. —Joey Nolfi, Entertainment Weekly, 10 Oct. 2025

Opponents are 11-for-12 against Notre Dame on third/fourth down when needing just a yard, without the help of the Wildcat. —Pete Sampson, New York Times, 10 Oct. 2025

Laws created through ballot initiatives require three-fourths approval to be amended by the Legislature, according to Michigan's constitution. —Arpan Lobo, Freep.com, 8 Oct. 2025

Try about one and one-fourth cups of unpacked oat flour for every one cup of unpacked all-purpose flour. —Jillian Kubala, Health, 6 Oct. 2025

Word History

Etymology

see four

First Known Use

1594, in the meaning defined at sense 2

Phrases Containing fourth

• a poor second/third/fourth
• fourth dimension
• fourth estate
• fourth trimester
• fourth wall
• fourth world
• sixty-fourth note
• sixty-fourth rest

Rhymes for fourth

• henceforth
• thenceforth

Kids Definition

fourth

noun

ˈfō(ə)rth 

ˈfȯ(ə)rth

1

: one that is number four in a series see number

2

: the difference in pitch between the first tone and the fourth tone of a scale

fourth adjective or adverb

fourthly adverb