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