The possessor of a master's degree.
Master; sir: a title used in the Middle Ages, given to a person in authority, or to one having a licence from a university to teach philosophy and the liberal arts.
A governing official in various institutions
An official charged with supervisory duties or with the enforcement of specific laws or regulations; such as a game warden or air-raid warden
A variety of pear.
A chief administrative officer of a prison.
To carry out the duties of a warden.