= 見返り。
Quid pro quo ("something for something" or "this for that" in Latin)[1] means an exchange of goods or services, where one transfer is contingent upon the other. English speakers often use the term to mean "a favour for a favour"; phrases with similar meaning include: "give and take", "tit for tat", and "you scratch my back, and I'll scratch yours".
FBIと国務省の間でヒラリーのemailの機密レベルを解くように密約がなされたのではないか、その際「見返り」が提供されたのでは、という疑惑。
最終ディベート前の、教科書通りのアリゲーション。