pitting vs erosion

pitting and erosion both are nouns.

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

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

pitting: the formation of small pits in a surface as a consequence of corrosion
erosion: erosion by chemical action

Other hypernyms of pitting include corroding, corrosion.

pitting (noun)	erosion (noun)
the formation of small pits in a surface as a consequence of corrosion	(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