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eighteenth

American  
[ey-teenth] / ˈeɪˈtinθ /

adjective

  1. next after the seventeenth; being the ordinal number for 18.

  2. being one of 18 equal parts.


noun

  • eighteenths
    plural
  1. an eighteenth part, especially of one (1/18).

  2. the eighteenth member of a series.

eighteenth British  
/ ˈeɪˈtiːnθ /

adjective

  1. (usually prenominal)

    1. coming after the seventeenth in numbering or counting order, position, time, etc; being the ordinal number of eighteen: often written 18th

    2. ( as noun )

      come on the eighteenth

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

noun

    1. one of 18 approximately equal parts of something

    2. ( as modifier )

      an eighteenth part

  1. the fraction that is equal to one divided by 18 ( 1/ 18 )

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Noun Inflected Forms

Etymology

Origin of eighteenth

before 900; Middle English eightenthe, eightethe, Old English eahtatēotha. See eighteen + -th 2

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The Dow Jones Industrial Average reached 48,500 points, marking its eighteenth record high of the year, reflecting market optimism.

From Barron's Dec. 11, 2025

"Since women had no political position in the eighteenth century, I could not place this debate there," Wills told Salon.

From Salon Oct. 11, 2024

The Garrick was founded in 1831, named after famous eighteenth century actor David Garrick.

From BBC Mar. 20, 2024

The scrolls were discovered in the eighteenth century, when workmen came across the remains of a luxury villa that might have belonged to the family of Julius Caesar’s father-in-law.

From Scientific American Oct. 17, 2023

When Napoleon, the French emperor, invaded Italy at the end of the eighteenth century, he arrived with lists of what he wanted: hundreds of paintings, prints, sculptures.

From "The Mona Lisa Vanishes" by Nicholas Day

The faces of the volutes must recede from the edge of the abacus inwards by one and a half eighteenths of that same amount.

From The Ten Books on Architecture by Vitruvius Pollio

"There aren't two eighteenths of October in one year."

From A Sheaf of Corn by Mary E. Mann

As William II himself puts it, this day, like all the "eighteenths" that went before it, has its special significance.

From The Schemes of the Kaiser by Juliette Adam

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