compaction vs concretion

compaction and concretion both are nouns.

Word	Noun	Adjective	Verb	Adverb
compaction	Yes	No	No	No
concretion	Yes	No	No	No

As nouns, compaction and concretion are synonyms defined as:

Other synonyms of compaction include compression, densification.

compaction (noun)	concretion (noun)
the act of crushing	the union of diverse things into one body or form or group; the growing together of parts
an increase in the density of something	an increase in the density of something
	a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body
	the formation of stonelike objects within a body organ (e.g., the kidneys)