Cosignatory
ahd-5
adjective.
Signed jointly.
noun.
One who cosigns.
The Century Dictionary and Cyclopedia
Uniting with another or others in signing, as a treaty or agreement: as,
cosignatory
powers.
noun.
One who unites with another or others in signing a treaty or agreement.
Wiktionary, Creative Commons Attribution/Share-Alike License
adjective.
signed
or
signing
jointly
noun.
Any of several people who
sign
a document together (especially a
treaty
)
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
signing jointly with others
noun.
one of two or more signers of the same document (as a treaty or declaration)
Word Usage
"“Remember how I tricked you into signing me on as a cosignatory on your home-equity loan?”"
Equivalent
joint
Hypernym
Words that are more generic or abstract
signatory
signer