/ Thesaurus / 1 Synonyms of 13th Find synonyms for: Adjective1. thirteenth, 13th, ordinal (vs. cardinal)usage: coming next after the twelfth in positionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: labyrinth Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language