n.1 the act or an instance of assuming.
2 a the act or an instance of accepting without proof. b a thing assumed in this way.
3 arrogance.
4 (Assumption) a the reception of the Virgin Mary bodily into heaven, according to Roman Catholic doctrine. b the feast in honour of this (15 August).
Etymology: ME f. OF asompsion or L assumptio (as ASSUME, -ION)