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 melee is "A tumultuous fight among several people." Used in a sentence: After the game, a melee broke out between fans of the opposing teams.

The definition for perception is "Capacity for seeing or understanding." Used in a sentence: His incredible perception made him the best detective on the force.

The definition for procrastinate is "To put off intentionally." Used in a sentence: Yvonne's father urged, "Don't procrastinate. Clean your room right away."

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.