beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
illuminate
The definition for illuminate is "To make clear." Used in a sentence: Her excellent lecture illuminated the complicated subject of nuclear physics.
oblivious
The definition for oblivious is "Lacking awareness." Used in a sentence: Love–struck Charlie was oblivious to everyone but the object of his affection.
recrimination
The definition for recrimination is "A retaliatory accusation." Used in a sentence: Frank, who was wounded by Sally's remark, made a bitter recrimination.
revoke
The definition for revoke is "To cancel by taking back." Used in a sentence: After Kal's father revoked his allowance, he had no money for the movies.