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

Rafael Devers, though, singled to center to lead off the fourth for the Giants’ first hit, then Adames hammered a 97 mph Williams fastball over the right-center field wall for his 20th home run of the season and 200th of his career. — Curtis Pashelka, Mercury News, 20 Aug. 2026

Brendan Donovan had a two-run double for Seattle, and Dominic Canzone's RBI single got the Mariners within 6-4 in the fourth. — ABC News, 20 Aug. 2026

Lowe extended the lead to 2-0 with his shot to the seats in left field with two outs in the fourth. — CBS News, 19 Aug. 2026

Lowe extended the lead to 2-0 with his shot to the seats in left field with two out in the fourth. — Los Angeles Times, 19 Aug. 2026

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