Floating at random; not fastened by and kind of mooring; at the mercy of winds and currents; loose from normal anchorage A vessel is said to be adrift when she breaks away from her moorings, warfs, and so on
If something comes adrift, it is no longer attached to an object that it should be part of. Three insulating panels had come adrift from the base of the vehicle. = loose
If a boat is adrift, it is floating on the water and is not tied to anything or controlled by anyone. They were spotted after three hours adrift in a dinghy