cunning
The definition for cunning is "Showing clever insight." Used in a sentence: The general devised a cunning strategy to outfox the enemy.
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.
duplicity
The definition for duplicity is "Deceptive thought, speech, or action." Used in a sentence: The life of an undercover detective is filed with necessary duplicity.
facade
The definition for facade is "false or superficial appearance." Used in a sentence: Emily's smile is just a facade masking her broken heart.
gargantuan
The definition for gargantuan is "Gigantic." Used in a sentence: The gargantuan monster towered over the ten–story bulding.