n. 1. The cardinal number that is equal to the sum of 12 + 1. 2. The 13th in a set or sequence. 3. Something having 13 parts, units, or members. [Middle English thyrtene, alteration of thrittene, from Old English thrēotīne; see trei- in the Appendix of Indo-European roots.] thir·teen adj. & pron. |
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.