thirteen

UK: /ˌθɜː^rˈtiːn/ US: /ˈθɝˈtin/ ,(thûr′tēn′)

WordReference Random House Learner's Dictionary of American English © 2026

thir•teen /ˈθɜrˈtin/   n. [countable]

1. a cardinal number, 10 plus 3.
2. a symbol for this number, as 13 or XIII.
3. a set of this many persons or things.

adj. [before a noun]

4. amounting to 13 in number.

thir•teenth, adj. 

WordReference Random House Unabridged Dictionary of American English © 2026

thir•teen  (thûr′tēn′), n. 

1. a cardinal number, 10 plus 3.
2. a symbol for this number, as 13 or XIII.
3. a set of this many persons or things.

adj. 

4. amounting to 13 in number.

• bef. 900; late Middle English thirttene, variant of Middle English thrittene, Old English thrēotēne; cognate with Dutch dertien, German dreizehn, Old Norse threttān. See three, -teen

Collins Concise English Dictionary © HarperCollins Publishers::

thirteen / ˈθɜːˈtiːn/ noun

1. the cardinal number that is the sum of ten and three and is a prime number
   See also number1
2. a numeral, 13, XIII, etc, representing this number
3. something represented by, representing, or consisting of 13 units

determiner

1. amounting to thirteen
2. (as pronoun): thirteen of them fell

Etymology: Old English threotēne; see three, -teen