The definition for hedonism is "Belief that pleasure is the sole aim of life." Used in a sentence: The hedonism of the emperoro, who spent all his time giving parties, caused his downfall.

The definition for illuminate is "To make clear." Used in a sentence: Her excellent lecture illuminated the complicated subject of nuclear physics.

The definition for impenitent is "Lacking remorse." Used in a sentence: The impenitent criminal received a harsh penalty, but his remorseful accomplice was released.

The definition for melodious is "Having a pleasing melody." Used in a sentence: The melodious sounds of the symphony soothed Tim after his trying day.

The definition for moderate is "Tending toward the average." Used in a sentence: The best–selling writer was disappointed; his new novel was only a moderate success.