Without further context, it's difficult to give a precise English translation.
Here are some possibilities depending on the context:
* "De Jean" as a surname: This would simply be translated as "Jean" in English.
* "De Jean" as part of a name: This would be translated as "of Jean" or "Jean's" in English. For example, "Pierre de Jean" would be translated as "Peter of Jean" or "Peter Jean's".
* "De Jean" as a phrase: This would depend on the specific context. For example, "la maison de Jean" (Jean's house) would be translated as "Jean's house" in English.
Please provide more context if you'd like a more specific translation.