1) Abhorrer 2) Attestant 3) Attestator 4) Attestor 5) Cosigner 6) Endorser 7) Signatory 8) Xer 1) Annie Sullivan, notably 2) Button Gwinnett was one 3) Communicator 4) Endorser 5) Giver of an autograph 6) Hancock or Franklin 7) Hancock, notably 8) John Hancock was one 9) Loan officer, often 10) Maker or endorser 11) Negotiation figure 12) One who talks with his hands 13) Petition supporter 
• (n.) One who signs or subscribes his name; as, a memorial with a hundred signers.
Sign'er noun One who signs or subscribes his name; as, a memorial with a hundred signers . 
[n] - someone who can use sign language to communicate 2. [n] - someone who signs and is bound by a document
signatory noun someone who signs and is bound by a document