/ Dictionary / Index T thirteen: Meaning and Definition of Find definitions for: thir•teen Pronunciation: (thûr'tēn'), [key] — n. a cardinal number, 10 plus 3. a symbol for this number, as 13 or XIII. a set of this many persons or things. —adj. amounting to 13 in number. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thirteen (Thesaurus) thirsty thirteen-lined ground squirrel Related Content Daily Word Quiz: serendipity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language