eating away vs wearing away

eating away and wearing away both are nouns.

Word	Noun	Adjective	Verb	Adverb
eating away	Yes	No	No	No
wearing away	Yes	No	No	No

As nouns, eating away and wearing away are synonyms defined as:

eating away and wearing away: (geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively

Other synonyms of eating away include eroding, erosion, wearing.

eating away (noun)	wearing away (noun)
(geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively	(geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively