It's the present tense, third person singular form of the verb "mediate".
Here's what "mediate" means and how it works in sentences:
* To mediate means to act as an intermediary between people or groups in a dispute, trying to help them reach an agreement.
Examples:
* "The UN is mediating peace talks between the two countries."
* "The teacher mediated the argument between the two students."
Let me know if you have any other questions!