detrition vs eating away

detrition and eating away both are nouns.

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

As nouns, eating away is a hypernym of detrition; that is, eating away is a word with a broader meaning than detrition:

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

Other hypernyms of detrition include eroding, erosion, wearing, wearing away.

detrition (noun)	eating away (noun)
effort expended in moving one object over another with pressure	(geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively
the wearing down of rock particles by friction due to water or wind or ice
erosion by friction