When you ablate something, you wear it away by rubbing or some other method. In medicine, doctors sometimes need to ablate a patient's skin to help it heal.
The verb ablate is often used in many different sciences — in each case, it has a slightly different sense, although its basic meaning is always to erode or otherwise wear away a substance. One way for physicians to treat heart disease is to ablate the inside of an artery using a tiny drill-like tool, and geologists study the way processes like evaporation and erosion can ablate — or remove the surface of — a glacier. The Latin root word is ablationem, "a taking away."