Meaning

noun an increase by natural growth or addition

noun something contributing to growth or increase

noun (astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases

originPIE word *h₂éd Learned borrowing from Latin accrētiō (“increase, increment”) + English -ion (suffix forming nouns denoting actions or processes, or their results). Accrētiō is derived from accrēscō (“to grow, increase”) + -tiō (suffix forming nouns denoting actions or processes, or their results); and accrēscō is from ac- (a variant of ad-, prefix meaning ‘to’, or having an intensifying effect) +…

Etymology from Wiktionary, CC BY-SA 3.0