From Longman Dictionary of Contemporary Englishaccretionac‧cre‧tion /əˈkriːʃən/ noun [countable, uncountable] formal1a layer of a substance which slowly forms on something2a gradual process by which new things are added and something gradually changes or gets biggerExamples from the Corpusaccretion• The public sector continued to grow through a process of bureaucraticaccretionfinanced by economicgrowth.• This is perhaps because the later accretions are somewhat dwarfed amid the toweringGothicarchitecture.• The surface of the Moon is the result of accretion and of subsequentimpacts and slow-acting erosional processes.• Erosion or accretion of sand by wind action is evident throughout and soilgenesis is truncated by erosion or fossilised by deposition.• Coral growth and the accretion of sediments in coastalmangroves will compensate.From Longman Business Dictionaryaccretionac‧cre‧tion /əˈkriːʃən/ noun [countable, uncountable]a slow, gradual increase in an amount, level, value etcWe will solve our trade problem not by big contracts, but by an accretion of hundreds of smaller deals.Originaccretion(1600-1700)Latinaccretio, from accrescere, from ad-“to” + crescere“to grow”