Appliance, n.
1. The act of applying; application; [Obs.] subservience. Shak.
2. The thing applied or used as a means to an end; an apparatus or device; as, to use various appliances; a mechanical appliance; a machine with its appliances.
Shades of meaning
Fernald has no entry of its own for appliance; he lists it under tool.
Where he writes about it:
An appliance is that which is or may be applied to the accomplishment of a result, either independently or as subordinate to something more extensive or important; every mechanical tool is an appliance, but not every appliance is a tool; the traces of a harness are appliances for traction, but they are not tools. — from tool