/ prɪˈzʌmpʃn; NAmE / noun
1.
[ C ] something that is thought to be true or probable :
There is a general presumption that the doctor knows best.
2.
[ U ] ( formal ) behaviour that is too confident and shows a lack of respect for other people
3.
[ U , C ] ( law ) the act of supposing that sth is true, although it has not yet been proved or is not certain :
Everyone is entitled to the presumption of innocence until they are proved to be guilty.
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WORD ORIGIN
Middle English : from Old French presumpcion , from Latin praesumptio(n) anticipation, from the verb praesumere anticipate (in late Latin take for granted), from prae before + sumere take.