Erosions

noun

1. The result of having been worn away or eroded, as by a glacier on rock or the sea on a cliff face.
2. The changing of a surface by mechanical action, friction, thermal expansion contraction, or impact.
3. The gradual loss of something as a result of an ongoing process.

   "the erosion of a person's trust"

4. Destruction by abrasive action of fluids.
5. (image processing) One of two fundamental operations in morphological image processing from which all other morphological operations are derived.