beach erosion vs erosion

beach erosion and erosion both are nouns.

Word	Noun	Adjective	Verb	Adverb
beach erosion	Yes	No	No	No
erosion	Yes	No	No	No

As nouns, erosion is a hypernym of beach erosion; that is, erosion is a word with a broader meaning than beach erosion:

beach erosion: the erosion of beaches
erosion: (geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively

Other hypernyms of beach erosion include eating away, eroding, wearing, wearing away.

beach erosion (noun)	erosion (noun)
the erosion of beaches	(geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively
	erosion by chemical action
	a gradual decline of something
	condition in which the earth's surface is worn away by the action of water and wind