Breadcrumb Home > Thesaurus > P Synonyms of pecos Find synonyms for: Noun1. Pecos, Pecos Riverusage: a tributary of the Rio Grande that flows southeastward from New Mexico through western TexasWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of pecos (Dictionary) ✖ Related Content Daily Word Quiz: temporize Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language