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.
Meaning Medical Patent. The word 'patent' has at least three meanings in the medical industry. These meanings include: 1  Open or unblocked-the throat patent (or unblocked). 2  A government license restricting use by others-patented heart valve.3  Drug covered by a patent or trademark-patent drugs vs off-patent drugs.eaning 1: Patent = open/unblocked. Patent has a medical meaning of open or unblocked, particularly regarding an unblocked tube. Common usage includes a 'patent airway', or 'patent fallopian tubes'.