adj. Like the tail of a fish; acting, or producing something, like the tail of a fish. Fish-tail burner, a gas burner that gives a spreading flame shaped somewhat like the tail of a fish. - Fish-tail propeller (Steamship), a propeller with a single blade that oscillates like the tail of a fish when swimming. - The lateral movement of the rear of a motor vehicle in a skid. A controlled movement of an airplane to reduce speed