What is Invention?

Legal Definition
An invention is a unique or novel device, method, composition or process. The invention process is a process within an overall engineering and product development process. It may be an improvement upon a machine or product or a new process for creating an object or a result. An invention that achieves a completely unique function or result may be a radical breakthrough. Such works are novel and not obvious to others skilled in the same field. An inventor may be taking a big step in success or failure.

Some inventions can be patented. A patent legally protects the intellectual property rights of the inventor and legally recognizes that a claimed invention is actually an invention. The rules and requirements for patenting an invention vary from country to country and the process of obtaining a patent is often expensive.

Another meaning of invention is cultural invention, which is an innovative set of useful social behaviours adopted by people and passed on to others. The Institute for Social Inventions collected many such ideas in magazines and books. Invention is also an important component of artistic and design creativity. Inventions often extend the boundaries of human knowledge, experience or capability.
-- Wikipedia
Legal Definition
A contrivance; a discovery. It is in this sense this word is used in the patent laws of the United States. 17 Pet. 228; S. C. 1 How. U. S. 202. It signifies not something which has been found ready made, but something which, in consequence of art or accident, has been formed; for the invention must relate ot some new or useful art, machine, manufacture, or composition of matter, not before known or used by others. Act of July 4, 1836, 4 Sharsw. continuation of Story's L. U.S. 2506; 1 Mason, R. 302; 4 Wash. C. C. R. 9. Vide Patent. By invention, the civilians understand the finding of some things which had not been lost; they must either have abandoned, or they must have never belonged to any one, as a pearl found on the sea shore. Lec. Elem 350.
-- Bouviers Law Dictionary
Legal Definition
In patent law. The act or operation of finding out something new; the process of contriving and producing something not previously known or existing, by the exercise of independent investigation and experiment. Also the article or contrivance or composition so invented. See Lei-dersdorf v. Flint, 15 Fed. Cas. 260; Smith v. Nichols, 21 Wall. 118, 22 In Ed. 566; Hollister v. Manufacturing Co., 113 U. S. 72, 5 Sup. Ct. 717, 28 In Ed. 901; Murphy Mfg. Co. v. Excelsior Car Roof Co. (C. C.) 70 Fed. 495. An "invention" differs from a "discovery." The former term is properly applicable to the contrivance and production of something that did not before exist; while discovery denotes the bringing into knowledge and use of something which, although it existed, was before unknown. Thus, we speak of the "discovery" of the properties of light, electricity, etc., while the telescope and the electric motor are the results of the process of "invention."
-- Black's Law Dictionary
Legal Definition
The finding out, creation or contrivance of something new and useful. See 20 Fed. Cas. (U. S.) 286.
-- Ballentine's Law Dictionary