A thing that is accepted as true or as certain to happen, without proof. The assumption that the meeting would be canceled was incorrect.
The action of taking on power or responsibility. His assumption of the role of manager was met with enthusiasm by the team.
The act of taking possession of something. The assumption of the throne by the new king was celebrated throughout the kingdom.
The undertaking of another's debt or obligation. The lender approved the buyer's assumption of the existing mortgage.
Arrogant or presumptuous behavior; effrontery. Her assumption in speaking for everyone offended the committee.