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.
medicine. 1. any drug or remedy. 2. the art and science of the diagnosis and treatment of disease and the maintenance of health. 3. the nonsurgical treatment of disease. alternative medicine see complementary and alternative medicine.