Attestor and Onlooker

Attestor noun - (law) a person who attests to the genuineness of a document or signature by adding their own signature.

Onlooker and attestor are semantically related. in witness topic. In some cases you can use "Onlooker" instead a noun "Attestor", when it comes to topics like person who observes an event.

Onlooker noun - Someone who sees or watches something.

Attestor and onlooker are semantically related. You can use "Attestor" instead a noun "Onlooker".