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.
physical medicine in Medicine. physical medicine n. The branch of medicine that deals with the treatment, prevention, and diagnosis of disease by essentially physical means, including manipulation, massage, and exercise, often with mechanical devices, and the application of heat, cold, electricity, radiation, and water.