DICT.TW Dictionary Taiwan

 co·sign·er /ˈkoˌsaɪnɚ/

 cosigner
      n 1: one of two or more signers of the same document (as a treaty
           or declaration) [syn: cosignatory]
      2: a signer in addition to the principal signer (to verify the
         authenticity of the principal signature or to provide
         surety)