Mammoth Cave, the world's longest known cave system. The following is a list of the world's 10 longest caves per length of documented passageways. Many passageways are still being discovered; this list is based on the latest verifiable data.
patent medicine - medicine that is protected by a patent and available without a doctor's prescription. medicament, medication, medicinal drug, medicine - (medicine) something that treats or prevents or alleviates the symptoms of disease. nostrum - patent medicine whose efficacy is questionable.
Full Definition of PATENT. 1. a: open to public inspection âused chiefly in the phrase letters patent b (1) : secured by letters patent or by a patent to the exclusive control and possession of a particular individual or party. 2. 3. : making exclusive or proprietary claims or pretensions. 4.ull Definition of PATENT. 1. : an official document conferring a right or privilege: letters patent. 2. a: a writing securing for a term of years the exclusive right to make, use, or sell an invention b: the monopoly or right so granted c: a patented invention. 3.