concretion

Sense 1 noun

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

Sense 2 noun

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

Sense 3 noun

an increase in the density of something

Sense 4 noun

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