BACK OF

prep. 1. In or at the rear of; to the back of; behind. The garage is hack of the house. Our car was in hack of theirs at the traffic light. 2. informal Being a cause or reason for; causing. Hard work was back of his success. The principal tried to find out what was back of the trouble on the bus. 3. informal In support or encouragement of; helping, clones will be elected because many powerful men are back of him. Get in back of your team by cheering them at the game.