To make valid by formal authoritative assent (a thing already instituted or ordained); to ratify, sanction.

transitive. To make (a thing) certain; to guarantee as certain, attest in an authoritative manner; to give certain information of. (Often with clause…

To attest (a thing) with some authority, to corroborate, confirm. Obsolete.

transitive. To vouch for the truth or reality of; to attest. Obsolete.

transitive. To declare or confirm the truth or correctness of (a statement, etc.).

To attest, confirm, ratify (as with a sign or seal). Obsolete.

To give legal or formal confirmation to; to confirm (a law, legal act, etc.).

transitive. To bear witness to, affirm the truth or genuineness of; to testify, certify. Const. simple object, subordinate clause, infinitive phr.…

To accredit, authenticate, prove trustworthy.

To attest.

transitive. colloquial you can quote me and variants; also don't quote me.