Simple Definition of cosign

from our Learner's Dictionary

cosign

verb

ˈkoʊˌsaɪn
cosigns; cosigned; cosigning
: to sign a document saying that you agree to share the responsibility for a loan or contract with another person
My mother cosigned the loan on my car.
cosign a lease
She cosigned for my car.

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“Cosign.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/cosign. Accessed 19 Jun. 2026.

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