Signer (noun)
One who signs something.
“John Hancock is a famous signer of the Declaration of Independence.”
“signatory”
Signer (noun)
One who uses sign language.
Signor (noun)
A courtesy title for a man of Italian origin.
Wiktionary
Signor (noun)
a title or form of address used of or to an Italian-speaking man, corresponding to Mr or sir
“Signor Ugolotti”
“I am a man of honour, Signor”
Oxford Dictionary