Duplicity means deliberate deceitfulness in speech or behavior.
Duplicity is a noun.
Synonyms: guile, trickery, cunning, deceit, fraud, falseness, deception, dishonesty.
Antonyms: candor, honesty, straightforward, veracity.
The duplicitous political leader consistently voted to raise taxes even though he said he was in favor of tax reductions.
The professional double-agent was a master of duplicity.
The duplicity of the board members involved in the scandal was shocking.
The jury was convinced that the culprit was guilty after they saw the duplicity of his actions.