Breadcrumb Home > Thesaurus > C Synonyms of cosign Find synonyms for: Verb 1. co-sign, cosign, validate, formalize, formalise usage: sign jointly; "Husband and wife co-signed the lease" 2. cosign, co-sign, endorse, indorse usage: sign and endorse (another person's signature), as for a loan WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of cosign (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: rort Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language