1. An increase by natural growth or addition
   "The accretion of knowledge over time led to significant scientific breakthroughs";
   - accumulation
    
2. Something contributing to growth or increase
   "he scraped away the accretions of paint"; "the central city surrounded by recent accretions"
    
3. (biology) growth by addition as by the adhesion of parts or particles
   "The accretion of calcium in the joints is a symptom of certain medical conditions"
    
4. (geology) an increase in land resulting from alluvial deposits or waterborne sediment
   "The accretion of silt at the river mouth created new habitable land"
    
5. (astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases
   "The accretion of dust and gas around the young star led to the formation of planets"
    
6. (law) an increase in a beneficiary's share in an estate (as when a co-beneficiary dies or fails to meet some condition or rejects the inheritance)
   "The sole surviving heir received an accretion to his share of the estate"

Derived forms: accretions

Type of: addition, gain, growth, heritage, increase, increment, inheritance

Encyclopedia: Accretion