derivative
The definition for derivative is "Lacking originality." Used in a sentence: Critics panned the movie as a derivative version of last year's Best Picture.
fidelity
The definition for fidelity is "State of being faithful." Used in a sentence: Unlike her fickle friend Benji, May Belle was known for her fidelity.
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.
inauspicious
The definition for inauspicious is "Not favorable." Used in a sentence: Gary believed the black foreboding sky was an inauspicious sign.
retroactive
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.