Definition of ablations:
(n) :
(surgery) The surgical removal of a body part, an organ, or especially a tumor; the removal of an organ function; amputation.
(n) :
(sciences) The progressive removal of material by any of a variety of processes such as melting or vaporization under heat or chipping.
(n) :
(meteorology) The depletion of surface snow and ice from a spacecraft or meteorite through melting and evaporation caused by aerodynamic heating.
(n) :
(geology) The removal of a glacier by melting and evaporation; the lowering of a land surface by any of several means, as in wind erosion or mass wasting.
(n) :
(obsolete) A carrying or taking away; removal.