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

The wealthiest one-fifth of Americans accounted for about 54% of earnings from 1990-99, the researchers found, a figure that had risen to 60% in the 2020-2025 period. —Christopher Rugaber, Fortune, 4 Feb. 2026

Rare earths are vital for defense and the energy transition, but China accounts for about three-fifths of global mining and 91% of refined output, and, after a recent diplomatic spat, Beijing banned exports of some products to Japan. —semafor.com, 3 Feb. 2026

The Lightning are first (with 74 points) and the Sabres fifth (69 points) in the Eastern Conference. —Data Skrive, New York Times, 3 Feb. 2026

Ethereum, the second-largest cryptocurrency, plunged even further, shedding nearly one-fifth of its value over the last week. —Max Zahn, ABC News, 2 Feb. 2026

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