twentieth

American  

[twen-tee-ith, twuhn-] / ˈtwɛn ti ɪθ, ˈtwʌn- /

adjective

1. next after the nineteenth; being the ordinal number for 20.

2. being one of 20 equal parts.

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noun

1. a twentieth part, especially of one (1/20).

2. the twentieth member of a series.

twentieth British  

/ ˈtwɛntɪɪθ /

adjective

1. (usually prenominal)

   1. coming after the nineteenth in numbering or counting order, position, time, etc; being the ordinal number of twenty: often written 20th

   2. ( as noun )

      he left on the twentieth

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noun

1. 1. one of 20 approximately equal parts of something

   2. ( as modifier )

      a twentieth part

2. the fraction that is equal to one divided by 20 ( 1/ 20 )

Etymology

Origin of twentieth

before 900; Middle English twentithe, Old English twentigotha. See twenty, -eth ²

Example Sentences

The concept of loading up on protein isn’t new per se — it first took off in the late twentieth century when diet and fitness cultures had both gone mainstream.

From Salon • May 7, 2026

German scientist Theodor Boveri first proposed this idea in the early twentieth century after studying cells under the microscope.

From Science Daily • Mar. 10, 2026

Television defined the last half of the twentieth century, outperforming all other mass media combined.

From Los Angeles Times • Jan. 22, 2026

One Pfizer medical director referred to the drug as the “‘snake oil’ of the twentieth century” in an email later made public.

From The Wall Street Journal • Dec. 25, 2025

His face was noble; a face sculpted from an aggrieved aristocracy that was bleeding out through weak tributaries in the long delta of the twentieth century.

From "The Great Santini" by Pat Conroy