Real Dictionary

patent
countable noun: A patent is an official right to be the only person or company allowed to make or sell a new product for a certain period of time.
verb: If you patent something, you obtain a patent for it.

patent in American English
open to examination by the public
adjective: protected by a patent; patented
noun: the exclusive right granted by a government to an inventor to manufacture, use, or sell an invention for a certain number of years
transitive verb: to take out a patent on; obtain the exclusive rights to (an invention, process, etc.) by a patent

patent in British English
to obtain a patent for
adjective: open or available for inspection (esp in the phrases letters patent, patent writ)
noun: a government grant to an inventor assuring him or her the sole right to make, use, and sell the invention for a limited period