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

Almost one-fifth of international visitors to Japan in 2024 came from China, or around 7 million people, according to provisional data from the Japan National Tourism Organization. —Lee Ying Shan, CNBC, 17 Nov. 2025

The Strait of Hormuz is a critical passage for global oil shipments, with roughly one-fifth of the world's petroleum passing through the waterway. —MSNBC Newsweek, 15 Nov. 2025

About one-fifth of the total has been for safety initiatives, largely in response to an epidemic of fatalities that make Brightline the deadliest major passenger train in the country. —Aaron Leibowitz, Miami Herald, 13 Nov. 2025

In the first half of 2025, close to one-fifth of the over 1,600 venture deals in climate tech were made by corporations for strategic reasons, such as technology access, supply chain integration, or future product offerings. —Lily Hsueh, The Conversation, 13 Nov. 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