A machine is a thermodynamic system that uses power to apply forces and control movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to natural biological macromolecules, such as molecular machines.
MACHINE definition: an apparatus consisting of interrelated parts with separate functions, used in the performance of some kind of work. See examples of machine used in a sentence.
(figuratively) A person or organisation that seemingly acts like a machine, being particularly efficient, single-minded, or unemotional. Bruce Campbell was a "demon-killing machine" because he made quick work of killing demons. The government has become a money-making machine.
any of various devices that dispense things: a vending machine for hot coffee or tea. Government a group of persons that controls a political party: the Democratic party machine.
A machine is a device with several parts that work together to perform a task. A machine can augment or replace the efforts required by an animal or human to make it easier to complete a task. For example, a car is a complex machine that transports humans and other things.