1) Authority 2) One signing off 3) Rubber stamp 
• (n.) An informer; an accuser. • (n.) One who approves. Formerly, one who made proof or trial. • (n.) One who confesses a crime and accuses another. See 1st Approvement, 2. • (v. t.) A bailiff or steward; an agent.
Ap·prov'er noun 1. One who approves. Formerly, one who made proof or trial. 2. An informer; an accuser. [ Obsolete] Chaucer. 3. (Eng. Law) One who confesses a crime and accuses another. See 1st Approvement , 2. 
[n] - an authority with power to approve
approver 1. Someone who approves. 2. Old English Law: An accomplice to a felony who confessed his or her guilt and gave evidence against his or her confederates.
noun an authority with power to approve
a person who approves. · an accomplice to a felony who confesses his or her guilt and gives evidence against his or her confederates.