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 beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.

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 immoderate is "Beyond usual or proper limits." Used in a sentence: Bob's immoderate appetite shocked the guests at the wedding banquet.

The definition for stifle is "To repress or discourage." Used in a sentence: Amy tried ineffectively to stifle her giggles after she read Susan's note in class.