Definition of "signatory"

signatory

/ˈsɪɡ.nə.tɹi/

noun
plural signatories
1. One who signs or has signed something.
  Quotations
  [...] it is reported that signatories of a petition for retention of service include the Home Secretary, Mr. R. A. Butler, who resides in the neighbourhood.
  1961 April, “Talking of Trains”, in Trains Illustrated, page 195
adjective
not comparable
1. Relating to a seal; used in sealing.
  Quotations
  signatory Rings
  1647, Samuel Torshell, Design to Harmonize the Bible
2. Signing; joining or sharing in a signature.