An example of an assumption is that there will be food at a party.
Assumption of command.
Assumption of an obligation.
A valid assumption.
An example of assumption is the fulfillment of the duties of another person who has been fired from your company.
Assumption of a false theory.
Origin of assumption
- Middle English assumpcion from Latin assūmptiō assūmptiōn- adoption from assūmptus past participle of assūmere to adopt assume
From American Heritage Dictionary of the English Language, 5th Edition