ethical
The definition for ethical is "Conforming to accepted standards." Used in a sentence: Mary did the ethical thing and turned in the diamond necklace she found.
frugal
The definition for frugal is "Thrifty, cheap." Used in a sentence: The frugal shopper only bought items that were on sale.
futile
The definition for futile is "Without purpose, completely ineffective." Used in a sentence: Arguing with Andrew is futile because he never changes his mind.
negate
The definition for negate is "To make invalid." Used in a sentence: Paula negated Tiffany's argument by proving that her main premise was false.
surplus
The definition for surplus is "Excess." Used in a sentence: Trevor decided to freeze the surplus chili for next week's tailgate party.