Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun cosigner

2 senses of cosigner

Sense 1
cosigner, cosignatory -- (one of two or more signers of the same document (as a treaty or declaration))
       => signer, signatory -- (someone who signs and is bound by a document)

Sense 2
cosigner -- (a signer in addition to the principal signer (to verify the authenticity of the principal signature or to provide surety))
       => signer, signatory -- (someone who signs and is bound by a document)