thirteenth

American  

[thur-teenth] / ˈθɜrˈtinθ /

adjective

1. next after the twelfth; being the ordinal number for 13.

2. being one of 13 equal parts.

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noun

1. a thirteenth part, especially of one (1/13).

2. the thirteenth member of a series.

thirteenth British  

/ ˈθɜːˈtiːnθ /

adjective

1. (usually prenominal)

   1. coming after the twelfth in numbering or counting order, position, time, etc; being the ordinal number of thirteen: often written 13th

   2. ( as noun )

      Friday the thirteenth

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noun

1. 1. one of 13 equal or nearly equal parts of something

   2. ( as modifier )

      a thirteenth part

2. the fraction equal to one divided by 13 ( 1/ 13 )

3. music

   1. an interval of one octave plus a sixth See also interval

   2. short for thirteenth chord

Etymology

Origin of thirteenth

before 900; thirteen + -th ²; replacing Middle English thrittenthe ( see three, tenth), Old English thryttēotha ( see tithe)

Example Sentences

Friday, the Thirteenth author Lawson, himself a noted stock manipulator who used the mass media of his era to influence markets and make and lose a fortune, called it “the Wall Street hoodoo-day.”

From Barron's • Mar. 13, 2026

As the relatively sensible one, Gill, a constant companion to Jodie Whittaker’s Thirteenth Doctor, as in “Who,” is wonderful being astounded or upright.

From Los Angeles Times • Feb. 12, 2026

The United States has made momentous strides toward improving protections and conditions for workers since the Thirteenth Amendment was ratified in 1865.

From Salon • Jun. 19, 2024

"After finishing my work, I'm as exhausted as a squeezed lemon," Thirteenth quips.

From BBC • Mar. 12, 2024

In addition, the women pledged to collect one million signatures on a petition supporting the Thirteenth Amendment.

From "Votes for Women!" by Winifred Conkling