concretion

Noun

• the union of diverse things into one body or form or group; the growing together of parts

• 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
  • renal calculi can be very painful
    

• the formation of stonelike objects within a body organ (e.g., the kidneys)

Related words

• Synonyms: 
  coalescence , coalescency , coalition , conglutination , compaction , compression , densification , calculus