/euh sump"sheuhn/ , n.
1. something taken for granted; a supposition: a correct assumption.
2. the act of taking for granted or supposing.
3. the act of taking to or upon oneself.
4. the act of taking possession of something: the assumption of power.
5. arrogance; presumption.
6. the taking over of another's debts or obligations.
7. Eccles.
a. ( often cap. ) the bodily taking up into heaven of the Virgin Mary.
b. ( cap. ) a feast commemorating this, celebrated on August 15.
[ 1250-1300; ME assumpcioun, assompcioun, assumsion assumption- (s. of assumptio ), equiv. to assumpt ( us ) taken up (ptp. of assumere; see ASSUME) + -ion- -ION ]
Syn. 1, 2. presupposition. 1. hypothesis, conjecture, guess, postulate, theory. 3. presumption. 5. effrontery, forwardness.