A person who attests; a witness who officially confirms something is genuine or true (variant spelling of attester).
From Latin attestor (one who attests), from attestari (to bear witness). This is an alternative form to attester using the Latin agent suffix -or.
While 'attester' and 'attestor' mean the same thing, legal documents tend to prefer 'attestor' because it sounds more formal and Latin-derived, which gives it extra authority.
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