Approver

Ap·prov·er

Approver

n.
  1. One who approves. Formerly, one who made proof or trial.
  2. An informer; an accuser. [Obs.]
  3. One who confesses a crime and accuses another. See 1st Approvement, 2. (Eng. Law)

Approver

n.
  1. A bailiff or steward; an agent. (Eng. Law) [Obs.]