ghats3,
bay....the deep barking or howling of a dog or wolf, especially when attacking
to keep the wolves at bay.... (literally) to keep the wolves at a safe distance from you, so that they are only threatening you by baying or barking, and not actually attacking you physically
to keep the wolves at bay.....(figuratively) to keep someone or something unpleasant at a safe distance from you
"To keep the wolf from the door" is a related idiom meaning, " to have enough money to avoid starving, freezing, etc."