/ Dictionary / Index T Thirteenth Amendment: Meaning and Definition of Find definitions for: Thir'teenth Amend'ment Pronunciation: [key] an amendment to the U.S. Constitution, ratified in 1865, abolishing slavery. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thirteenth thirtieth Related Content Daily Word Quiz: reclusive Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language