Answer: eroder

AnswerCrossword Clue
ERODERWater or wind, e.g.
ERODERAcid, for one
ERODERStorm surf, vis-a-vis a beachfront
ERODERWind, over time
ERODERWind or water
ERODERSoil spoiler
ERODERAcid, water or wind, over time