1. The act of taking to or upon oneself: assumption of an obligation.
2. The act of taking possession or asserting a claim: assumption of command.
3. The act of taking for granted: assumption of a false theory.
4. Something taken for granted or accepted as true without proof; a supposition: a valid assumption.
5. Archaic Presumption; arrogance.
6. Logic A minor premise.
7. Assumption Christianity The taking up of the Virgin Mary into heaven in body and soul after her death, observed as a feast on August 15.
[Middle English assumpcion, from Latin assūmptiō, assūmptiōn-, adoption, from assūmptus, past participle of assūmere, to adopt; see ASSUME.]
(click for a larger image)Assumption
c. 1670 painting, The Assumption of the Virgin, by Bartolomé Esteban Murillo
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.