traitre

In a sentence

• Il était un traître à la cause, divulguant des secrets à l'ennemi.

  He was a traitor to the cause, divulging secrets to the enemy.

  Here, 'traître' is used to describe someone betraying a loyalty or allegiance, specifically in a context involving fidelity to a cause.

• Son sourire traître masquait ses véritables intentions.

  His deceitful smile masked his true intentions.

  In this sentence, 'traître' is used adjectivally (via derivation) to characterize an action or feature displaying betrayal or deceit.

• L'acte de trahison qu'il a commis était celui d'un véritable traître.

  The act of betrayal he committed was that of a true traitor.

  Here, 'traître' again describes someone who commits a betrayal, emphasizing the action that defines the term.