Noah Webster's Dictionary (n.) One who makes known or proclaims; that which exhibits.

Multi-Version Concordance Declarer (1 Occurrence) Amos 4:13 For, lo, the former of mountains, and creator of wind, And the declarer to man what 'is' His thought, He is making dawn obscurity, And is treading on high places of earth, Jehovah, God of Hosts, 'is' His name! (YLT)