concretion vs compaction

concretion and compaction both are nouns.

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

As nouns, concretion and compaction are synonyms defined as:

Other synonyms of concretion include compression, densification.

concretion (noun)	compaction (noun)
the union of diverse things into one body or form or group; the growing together of parts	the act of crushing
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)