a machine that can continue to do work indefinitely without drawing energy from some external source; impossible under the law of conservation of energy | any mechanical or electrical device that transmits or modifies energy to perform or assist in the performance of human tasks |
| a motor vehicle with four wheels; usually propelled by an internal combustion engine |
| a device for overcoming resistance at one point by applying force at some other point |
| a group that controls the activities of a political party |
| an intricate organization that accomplishes its goals efficiently |
| an efficient person |