apathetic
The definition for apathetic is "Showing little or no emotion." Used in a sentence: Carmine was concerned about his usually cheerful brother's apathetic attitude.
belated
The definition for belated is "Past the normal or proper time." Used in a sentence: Even though I forgot his birthday, I hoe my father accepts my belated card.
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.
dubious
The definition for dubious is "Questionable." Used in a sentence: Karl found Kevin's claim that he was sick dubious, as he had just seen him playing football.
flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.