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.
fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
prune
The definition for prune is "To reduce by removing excess." Used in a sentence: The candidate pruned his speech so he would not exceed the time limit.
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.
unscrupulous
The definition for unscrupulous is "Lacking principles." Used in a sentence: The unscrupulous salesman was fired for lying to his customers.