(1):

(n.) In the University of Oxford, an examiner for moderations; at Cambridge, the superintendant of examinations for degrees; at Dublin, either the first (senior) or second (junior) in rank in an examination for the degree of Bachelor of Arts.

(2):

(n.) A mechamical arrangement for regulating motion in a machine, or producing equality of effect.

(3):

(n.) One who, or that which, moderates, restrains, or pacifies.

(4):

(n.) The officer who presides over an assembly to preserve order, propose questions, regulate the proceedings, and declare the votes.