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

The Spurs led by 43 points in the third quarter, allowing the defending Western Conference champions to sit their starters and most of their key reserves for the entire fourth. — ABC News, 14 Nov. 2026

Brown had a three-point play and hit a three-pointer as part of a a 16-2 run that closed the third quarter and gave UCLA a 62-39 lead going into the fourth. — Los Angeles Times, 13 Nov. 2026

One-fourth to ½ inch of water should be applied before aerating your lawn. — Joshua Siskin, Oc Register, 12 Nov. 2026

Microsoft last month offered voluntary buyouts to some 60,000 employees, about one-fourth of its total workforce, as the company (like other big tech firms) looks to cut costs while also spending heavily on AI infrastructure. — Todd Spangler, Variety, 12 Nov. 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