accretion

UK: /əˈkriːʃ^ən/ US: /əˈkriʃən/ ,(ə krē′shən)

WordReference Random House Learner's Dictionary of American English © 2025

ac•cre•tion /əˈkriʃən/   n. 

1. an increase by growth or addition:
   [uncountable] gradual accretion of coral in the sea.
   [countable] an accretion of wealth.

WordReference Random House Unabridged Dictionary of American English © 2025

ac•cre•tion  (ə krē′shən), n. 

1. an increase by natural growth or by gradual external addition;
   growth in size or extent.
2. the result of this process.
3. an added part;
   addition:
   The last part of the legend is a later accretion.
4. the growing together of separate parts into a single whole.
5. Law increase of property by gradual natural additions, as of land by alluvion.

• Latin accrētiōn- (stem of accrētiō), equivalent. to accrēt(us), past participle of accrēscere to grow (ac- ac- + crē- grow + -tus past participle suffix) + -iōn- -ion
• 1605–15

ac•cre′tive, ac•cre′tion•ar′y, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

accretion / əˈkriːʃən/ noun

1. any gradual increase in size, as through growth or external addition
2. something added, esp extraneously, to cause growth or an increase in size
3. the growing together of normally separate plant or animal parts

Etymology: 17th Century: from Latin accretiō increase, from accrēscere. See accrue

acˈcretive, acˈcretionary adjective