At the mercy of somebody/something Definition 1 of 3Pro Tip 1/3Implies Helplessness Suggests being unable to change the situation or escape from it. Without electricity, we were at the mercy of the cold night. Pro Tip 2/3Negative Situations Often used when the situation is harmful or undesirable. The sailors were at the mercy of the storm. Pro Tip 3/3Lack of Control Highlights the absence of influence over the outcome. Patients awaiting transplants are at the mercy of donor availability.