attest vb[Latin attestari , from ad to + testari to call to witness, from testis witness]
: to bear witness to
: affirm to be true or genuine
: to authenticate (as a will) by signing as a witness
: to bear witness
: testify often used with to
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.