From Latin 'assūmere' (to take to oneself), from 'ad-' + 'sūmere' (to take), from 'sub-' + 'emere' (to take, to buy).
To take for granted without proof; to take on a responsibility, role, or quality; to seize or take possession of.
From Latin "assūmere" meaning "to take up, to take to oneself, to adopt," composed of "ad-" (to, toward) and "sūmere" (to take, to obtain). Latin "sūmere" is a contraction of "sub-emere" (to take from below), where "emere" means "to buy, to take." "Emere" derives from Proto-Indo-European *h₁em- (to take, to distribute), which also produced Old Irish "ar-fo-emat" (they accept) and Lithuanian "imti" (to take). The word entered English in the early 15th century through legal and theological Latin, initially meaning "to take upon oneself" (as in assuming
The Catholic feast of the Assumption celebrates Mary being 'taken up' into heaven — using the original Latin sense of 'assūmere.' The same root 'emere' (to take, to buy) hides inside 'example' (a thing taken out), 'exempt' (taken out, freed), 'premium' (a reward taken before), 'redeem' (to buy back), and 'consume' (to take completely).