machine (a piece of equipment with moving parts that is designed to do a particular kind of work): A washing machine is run by a small electric motor.
motor (a device that uses electricity or fuel to produce movement): The ceiling fan needs a new motor.
device (a piece of equipment that does a particular job): We sell satellite receivers, refrigerators, TVs, and other electronic devices.
engine (a machine that burns fuel to make something move): The car goes like a rocket since I put a new engine in it.
unit (a machine or part of a machine or system that does a particular job): This is the central heating unit. The central processing unit of the computer is not working.
appliance (a piece of equipment designed to perform a specific task): They repair modern heating appliances of all types.
contraption (a device or machine that looks strange or complicated): I don’t understand how this contraption works.