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. : 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.ull Definition of PATENT. transitive verb. 1. : to obtain or grant a patent right to. 2. : to grant a privilege, right, or license to by patent. 3.