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.
fraud
The definition for fraud is "Trick." Used in a sentence: The con man's fraud involved selling swampland to gullible investors.
gruff
The definition for gruff is "Rough or stern in manner or speech." Used in a sentence: Heidi's grandfather was gruff, barking stern orders and hardly smiling.
induce
The definition for induce is "To influence or cause." Used in a sentence: The loud blast of the cannon induced an avalanche.
unscrupulous
The definition for unscrupulous is "Lacking principles." Used in a sentence: The unscrupulous salesman was fired for lying to his customers.