1. in a deceitful or dishonest manner; with deliberate deception or double-dealing
Usage: formal; often used in legal or serious contexts

Examples

• The executive duplicitously promised transparency while secretly hiding financial records.
• She duplicitously agreed to the contract while planning to break its terms.
• He duplicitously presented himself as a friend while working against their interests.
• The company duplicitously marketed the product as safe despite knowing of serious defects.
• They duplicitously claimed to support the cause while funding its opposition.
• The diplomat duplicitously negotiated peace while preparing for conflict.