A federal agency under the auspices of the Department of Commerce, which grants and regulates patents and trademarks. patent (of invention) n. The granting of a right or authority by the federal government; the document granting that right or authority; an exclusive right to make, use, or sell an invention granted to the inventor of a unique device or process for a specified period of time (usually 20 years). See new and useful. design patent. Patent granted for a new appearance to an existin...