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 drub is "To defeat decisively." Used in a sentence: The powerful young boxer drubbed the longtime champion.

The definition for mediate is "To come between parties in order to reconcile." Used in a sentence: The diplomatic Henry was able to mediate between the quarreling sisters.

The definition for oblivious is "Lacking awareness." Used in a sentence: Love–struck Charlie was oblivious to everyone but the object of his affection.

The definition for pantomime is "Telling a story through gestures." Used in a sentence: The jealous actress called her understudy's performance a ridiculous pantomime.