What is Machine?

Legal Definition
A machine is a tool containing one or more parts that uses energy to perform an intended action. Machines are usually powered by chemical, thermal, or electrical means, and are often motorized. Historically, a power tool also required moving parts to classify as a machine. However, the advent of electronics has led to the development of power tools without moving parts that are considered machines.

A simple machine is a device that simply transforms the direction or magnitude of a force, but a large number of more complex machines exist. Examples include vehicles, electronic systems, molecular machines, computers, television, and radio.
-- Wikipedia
Legal Definition
A contrivance which serves to apply or regulate moving power; or it is a tool more or less complicated, which is used to render useful natural instruments, Clef. des Lois Rom. h. t.

2. The act of congress gives to inventors the right to obtain a patent right for any new and useful improvement on any art, machine, manufacture, &c. Act of congress, July 4, 1836, s. 6. See Pet. C. C. 394; 3 Wash. C. C. 443; 1 Wash. C. C. 108; 1 Wash. C. C. 168; 1 Mason, 447; Paine, 300; 4 Wash. C. C. 538; 1 How. U. S., 202; S. C. 17 Pet. 228; 2 McLean, 176.
-- Bouviers Law Dictionary
Legal Definition
In patent law. Any contrivance ufeed to' regulate or augment force or motion; more properly, a complex structure, consisting of a combination or peculiar modification, of the mechanical powers. The term "machine," in patent law, includes every mechanical device, or combination of mechanical powers and devices, to perform some function and produce a certain effect or result. But where the result or effect is produced by chemical action, by the operation or application of some element or power of nature, or of one substance to another, such modes, methods, or operations are called "processes." A new process is nsually the result of discovery ; a machine, of invention. Coming v. Burden, 15 How. 252, 207, 14 L. Ed. 683. And see Pittsburgh Reduction Co. v. Cowles Electric Co. (C. C.) 55 Fed. 316; Westinghouse v. Boyden Power Brake Co , 170 U. S. 537, 18 Sup. Ct. 707, 42 L. Eld. 1136 ; Burr v. Duryee, -1 Wall. 570, 17 L. Ed. 650; Steams v. Russell, 85 Fed. 225, 29 C. C. A. 121; Wintermute v. Redington, 30 Fed. Cas. 370. See Perfect machine.
-- Black's Law Dictionary
Legal Definition
Any mechanical device or combination of mechanical powers and devices to perform some function and produce a certain effect or result. See 56 U. S. 252, 14 L. Ed. 683.
-- Ballentine's Law Dictionary