ab·la·tion (?-bl??sh?n)n.1. Surgical excision or amputation of a body part or tissue.2. The erosive processes by which a glacier is reduced.3. Aerospace a. The dissipation of heat generated by atmospheric friction, especially in the atmospheric reentry of a spacecraft or missile, by means of a melting heat shield.b. The reduction or removal of heat-protective surface material by aerodynamic friction, as from a heat shield.[Late Latin abl?ti?, abl?ti?n-, from Latin abl?tus, past participle of auferre, to carry away : ab-, away; see ab-1 + l?tus, carried; see tel?- in Indo-European roots.]ab·la?tor n.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.ablation (æb?le???n) n1. (Surgery) the surgical removal of an organ, structure, or part2. (Aeronautics) the melting or wearing away of an expendable part, such as the heat shield of a space re-entry vehicle on passing through the earth’s atmosphere3. (Geological Science) the wearing away of a rock or glacier[C15: from Late Latin ablati?n-, from Latin auferre to carry away, remove]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ab?la?tion (æ?ble? ??n) n. 1. the act or process of ablating. 2. the removal of organs, abnormal growths, or harmful substances from the body by mechanical means, as by surgery. 3. the erosion of the protective outer surface (ablator) of a spacecraft or missile due to heat during reentry through the atmosphere. [1570?80;