accretion ac·cre·tion (ə-krē'shən)
Growth or increase in size by gradual external addition, fusion, or inclusion.
Increase by addition to the periphery of material of the same nature as that already present, as in the growth of crystals. Also called accrementition.
Foreign material, such as plaque or calculus, collecting on the surface of a tooth or in a cavity.
The growing together or adherence of body parts that are normally separate.