Syngraph

SYNGRAPH. A deed, bond, or other instrument of writing, under the band and seal of all the parties. It was so called because the parties wrote together.
     2. Formerly such writings were attested by the subscription and crosses of the witnesses; afterwards, to prevent frauds and concealments, they made deeds of mutual covenant in a script and rescript, or in a part and counterpart, and in the middle between the two copies they wrote the word syngraphus in large letters, which being cut through the parchment, and one being delivered to each party, on being afterwards put together, proved their authenticity.
     3. Deeds thus made were denominates syngraphs by the canonists, and by the common lawyers chirographs. (q.v.) 2 Blackstone's Commentaries, 296.