Attestative is a term used to refer to something that serves as proof or evidence. While it may not be a commonly used word, it is still important to know some synonyms that can be used in its place. Some good alternatives include corroborative, supporting, verifying, authenticating, and confirming. Each of these words can be used to describe something that provides evidence to support a claim or to prove something to be true. By choosing the right synonym for attestative, you can make your writing more impactful and expressive while getting your point across more effectively.