The definition for futile is "Without purpose, completely ineffective." Used in a sentence: Arguing with Andrew is futile because he never changes his mind. The definition for procrastinate is "to put off intentionally.", the definition for flaw is "An imperfection.", and the definition for combative is "Eager to fight."

The definition for retroactive is "effective as of a prior time or condition." Used in a sentence: The retroactive law made even past infractions punishable. The definition for raucous is "noisy, rowdy.", the definition for mundane is "Practical, ordinary.", and the definition for placebo is "An inactive substance used in medical testing."

The definition for comparable is "Similar, equivalent." Used in a sentence: Helen will only accept something of comparable value for her ticket to the concert. The definition for civility is "politeness.", the definition for commemorate is "To mark by a ceremony.", and the definition for gruff is "Rough or stern in manner or speech."

The definition for stern is "Harsh, severe." Used in a sentence: The stern principal canceled the prom after the seniors played a silly prank. The definition for periodic is "occurring at regular intervals.", the definition for combustion is "Act of burning.", and the definition for fickle is "Lacking constancy, changeable."

The definition for parity is "Equality." Used in a sentence: Hilda, to avoid squabbles, aimed for parity in the slices of birthday cake. The definition for oblivious is "lacking awareness.", the definition for regurgitate is "To pour out or throw back.", and the definition for avian is "Relating to birds."