brandish
The definition for brandish is "To shake or wave menacingly." Used in a sentence: The baseball player was fined for brandishing his bat at the opposing pitcher.
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.
impenitent
The definition for impenitent is "Lacking remorse." Used in a sentence: The impenitent criminal received a harsh penalty, but his remorseful accomplice was released.
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.