de ‧ ceit ‧ ful /dɪˈsiːtf ə l/ BrE AmE adjective
[ Word Family: noun : ↑ deceit , ↑ deceiver , ↑ deception ; adjective : ↑ deceitful , ↑ deceptive ; verb : ↑ deceive ; adverb : ↑ deceptively ]
someone who is deceitful tells lies in order to get what they want:
His manner was sly and deceitful.
—deceitfully adverb :
His lawyer argued that his client had not acted deceitfully.
—deceitfulness noun [uncountable]