Wiktionary
signator
alt. A signatory: someone who signs something. n. A signatory: someone who signs something.
Usage examples of "signator".
I was still a signator on the account, and I had planned on using some of it as a down payment on die house down the street for him and his wife.
He had managed by this time to complete a second edition of his Manuel, a slicker one than the first, carrying letters of endorsation from four bishops, including one unlikely signator, the Bishop of Walla Walla in the distant territory of Washington.