hold someone or something at bay
Fig. to make someone, a group, or an animal stay at a safe distance. (Originally referred only to animals.) I held the attacker at bay while Mary got away and called the police. The dogs held the bear at bay while I got my gun loaded.
hold at bay, to
To keep some adverse situation from worsening; to hold off an enemy. The term comes from the Old French tenir a bay, which meant to hold open or in suspense, and referred to a hunted animal being cornered by its pursuers. The term was used literally by the fourteenth century, and figuratively soon thereafter. It is also phrased as to keep at bay.