It is the hypothetical source of/evidence for its existence is provided by: Greek magis "kneaded mass, cake," mageus "one who kneads, baker;" Latin macerare "soften, make soft, soak, steep;" Lithuanian minkyti "to knead;" Old Church Slavonic mazo "to anoint, smear;" Breton meza "to knead;" Old English macian "to make, form, construct, do," German machen "to make;" Middle Irish maistir "to churn."
1610s, "bring into existence, make or cause to become real," also "exhibit the actual existence of," from French réaliser "make real" (16c.), from real "actual" (see real (adj.)). The sense of "understand clearly, comprehend the reality of" is recorded by 1775. Sense of "obtain, amass, bring or get into actual possession" (money, profit, etc.) is from 1753. Related: Realized; realizing.
late 15c., "that which is heaped up, an accumulated mass," from Latin accumulationem (nominative accumulatio) "a heaping up," noun of action from past-participle stem of accumulare "to heap up, amass," from ad "to," here perhaps emphatic (see ad-), + cumulare "heap up," from cumulus "heap" (from suffixed form of PIE root *keue- "to swell"). Meaning "act of heaping up" is from c. 1600.
