IPA: /ˈsaɪnər/
KK: /ˈsaɪnər/
A person who writes their name on a document or uses sign language to communicate.
The signer carefully wrote their name at the bottom of the contract.
Signer → It is formed from "sign" (from Latin "signum", meaning mark or sign) and "-er" (meaning a person who). A signer is a person who marks or signs a document.
Think of someone who makes a 'mark' ('sign') on a document — that's why a signer is a person who signs.