To jeopardize something is to put it in danger of being lost, spoiled, or badly hurt. You might jeopardize a job by lying, a friendship by gossip, or a plan by being careless. It is a fairly formal verb — news, offices, and school writing like it; friends more often say put at risk or put in danger. It needs an object, and that object is something that matters (a chance, a life, a deal), not a small everyday thing. British spelling is often jeopardise; the meaning is the same. Though actually the word only sounds right when the thing at risk is important — that weight is part of how people hear it.