How do you say second-party in French?

There isn't a direct, one-word translation for "second-party" in French. Instead, you would typically use a phrase depending on the context:

Formal:

* Partie tierce: This is the most literal translation, literally meaning "third party." This is used in legal or contractual contexts.

* Le deuxième intervenant: This means "the second intervener" and can be used when talking about parties involved in a process or agreement.

Informal:

* La deuxième partie: This means "the second party" and is a more general way of saying "second-party" in casual conversations.

Example:

* "Le contrat stipule que la partie tierce est responsable des dommages." (The contract states that the third party is responsible for damages.)

* "J'ai rencontré le deuxième intervenant lors de la réunion." (I met with the second party during the meeting.)

* "La deuxième partie a accepté nos conditions." (The second party agreed to our conditions.)

The best way to say "second-party" in French depends on the specific context and level of formality.