The definition for authoritarian is "Favoring absolute obedience to authority." Used in a sentence: Marco's authoritarian mother never allowed him to watch more than one hour of television a day.

The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer.

The definition for regurgitate is "To pour out or throw back." Used in a sentence: The teacher wanted us to examine ideas rather than to regurgitate memorized facts.

The definition for revive is "To bring back to life." Used in a sentence: Hank tried to revive Clare's interest in the project, but her enthusiasm had expired.

The definition for unscrupulous is "Lacking principles." Used in a sentence: The unscrupulous salesman was fired for lying to his customers.