Declarant

n. announcer, proclaimer

A declarant, generally speaking, is anyone who composes and signs a statement or alleging that the information he has given therein is true. This differs from an affiant, as in the case of an affidavit the facts therein are sworn to before an notary public or other official, whereas a declaration is usually made by one person for the use of another.
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n. declarer

v. declare, state, proclaim, profess, say, report, aver, predicate, represent, return, cut open, rule, register, adjudge, certify

n. declarant, announcer, proclaimer

(n.)
One who declares.