Also found in: Thesaurus, Legal, Financial, Wikipedia.
Related to cosign: cosine


to sign a document jointly with another; to endorse, as for a mortgage: his father cosigned the loan on his new car
Not to be confused with:
cosine – a mathematical term
Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree


tr.v. co·signed, co·sign·ing, co·signs
1. To sign (a document) jointly.
2. To endorse (another's signature), as for a loan.

co·sign′er n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


1. (tr) to sign (a document) jointly
2. (Banking & Finance) (intr) banking to sign a document that has already been signed by a borrower of money, declaring that, should the borrower be unable to repay that money, the signer will repay the amount due
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈkoʊˌsaɪn, koʊˈsaɪn)

v.i., v.t.
to sign as a cosigner.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Verb1.cosign - sign jointly; "Husband and wife co-signed the lease"
validate, formalise, formalize - declare or make legally valid
2.cosign - sign and endorse (another person's signature), as for a loan
endorse, indorse - sign as evidence of legal transfer; "endorse cheques"
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
When you cosign on a loan, you only get the liability aspect.
According to DocuSign, the acquisition builds on a three year business partnership between DocuSign and ARX, bringing together ARX's CoSign digital signature technology with DocuSign's Digital Transaction Management platform.
The refinery's spokesman Kenneth Gijsbertha and Angelo Meyer, president of the refinery workers' union PWFC, said Chavez was due to meet with Prime Minister Ivar Asjes to cosign a long awaited memorandum of understanding (MoU) on the future of the oil refinery in Curacao, reports the Curacao Chronicle (June 2, 2014).
New York, NY, January 31, 2014 --( CoSIGN TV Network is piloting an independent music video channel called STEAM - The Rise of Independent Music.
TELECOMWORLDWIRE-February 21, 2012-Yubico announces ARX CoSign digital signature function support for YubiKey(C)1994-2012 M2 COMMUNICATIONS
We're not entirely sure if we lost any poundage, but we do know that something deserves a heavy collective cosign when Mobolaji says "That's phat." TSD
My parents aren't in a position to cosign my loans, and I don't have an established credit history.
He persuaded his mother to let him use $7,500 of his savings and cosign on a used Lexus, but his fiancee and a few months of paying the weighty $900 car note persuaded him to begin looking for a home.
The cosign of each program with every other program in the sample averaged .48.
Law compares them to "your lovable ex-con brother-in-law who keeps wanting you to cosign the loan for his Jaguar" (August-September 2000, 63).
Robar's Angle Cosign indicator is a gadget that mounts on a riflescope to determine actual range when shooting at up or down angles.