Machiavellian:

1. Definition: Adjective. Referring to the characteristics of Niccolò Machiavelli, an Italian political philosopher, who suggested the use of deceit and cunning tactics to achieve and maintain political power.
2. Synonyms: Manipulative, cunning, scheming, crafty, duplicitous.
3. Antonyms: Honest, straightforward, sincere, transparent.
4. Example: The Machiavellian prince disguised his true intentions, manipulating his allies and enemies alike to achieve his political goals.