磨蚀

磨蚀	mó shí	erosion / abrasion
磨	mó	to rub / to grind / to polish / to sharpen / to wear down / to die out / to waste time / to pester / to insist
磨	mò	grindstone / to grind / to turn round
蚀	shí	to nibble away at sth / to eat into / to erode