fifth

noun

ˈfith  ˈfif(t)th 

ˈfift

plural fifths ˈfiths 

ˈfif(t)ths, 

ˈfif(t)s

1

: one that is number five in a series

Payment is due on the fifth of the month.

see Table of Numbers

2

: one of five equal parts of something

spent a fifth of their income on rent

3

a

: the musical interval embracing five diatonic degrees

b

: a tone at this interval

specifically : dominant sense 1

c

: the harmonic combination of two tones at this interval

4

: a unit of measure for liquor equal to one fifth of a U.S. gallon (0.757 liter)

5

the Fifth : the Fifth Amendment of the U.S. Constitution

also : the right accorded by the Fifth Amendment to refuse to testify against oneself see also plead the fifth, take the fifth

fifth adjective or adverb

the fifth annual food festival

She finished fifth in the race.

fifthly adverb

Fourthly, it takes a lot of concrete to make a nuclear power plant. Fifthly, there is no place to put the waste that is safe.

—Victor Odlivak

Examples of fifth in a Sentence

The bill is due on the fifth of each month.

She donated a fifth of her income to charity.

bought a fifth of whiskey

Recent Examples on the Web

One reason is that homes have been on a tear lately, increasing in value by about two-fifths over the first half of the decade. —Daniel De Visé, USA Today, 14 Dec. 2025

The Ministry of Education said in August that one-fifth of higher education programs nationwide have been revamped in the last two years — with a slew of majors cut or added — to channel more students into AI and integrated circuits fields. —Evelyn Cheng, CNBC, 10 Dec. 2025

The special is Epps’ fifth for the streamer, following Ready to Sell Out (2024), Indiana Mike (2022), Only One Mike (2019) and Don’t Take It Personal (2015). —Matt Grobar, Deadline, 10 Dec. 2025

One-fifth of companies surveyed reported no specific support efforts for moving women up in their careers. —Sasha Rogelberg, Fortune, 10 Dec. 2025

Word History

Etymology

Middle English fifte, fifthe, from Old English fīfta, from fīf five

First Known Use

1557, in the meaning defined at sense 2

Phrases Containing fifth

• fifth column
• fifth disease
• fifth wheel
• plead the fifth

Kids Definition

fifth

noun

ˈfith  ˈfif(t)th 

1

: one that is number five in a series see number

2

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

fifth adjective or adverb

fifthly adverb