[ uh-suhmp-shuhn ]
See synonyms for: assumptionassumptions on

  1. something taken for granted; a supposition: a correct assumption.

  2. the act of taking for granted or supposing.

  1. the act of taking to or upon oneself.

  2. the act of taking possession of something: the assumption of power.

  3. the taking over of another's debts or obligations.

  4. Ecclesiastical.

    • (often initial capital letter) the bodily taking up into heaven of the Virgin Mary.

    • (initial capital letter) a feast commemorating this, celebrated on August 15.

  5. Logic. the minor premise of a syllogism.

Origin of assumption

First recorded in 1250–1300; Middle English assumpcioun, assompcioun, assumsion, from Latin assūmptiōn- (stem of assūmptiō ), equivalent to assūmpt(us) “taken up” (past participle of assūmere ) + -iōn- noun suffix; see origin at assume, -ion

word story For assumption

The word assumption is a great example of how a word can take on new dimensions of meaning over time, while staying true to some aspect of its original sense.
assumption has been in the language since the 13th century, and was initially confined to a specific ecclesiastical meaning in the Catholic Church. The Latin word on which it is based literally means “the action of being taken up or received,” and in English assumption referred to the taking up into heaven of the Virgin Mary. That meaning still exists today, and in all the meanings it has assumed since then, one can see the common thread running through them is the sense of taking.
One early sense meant “arrogance,” as in this 1814 quote from Sir Walter Scott: “his usual air of haughty assumption.” Arrogance is a taking upon oneself a conviction of self-importance. Later senses arose having to do with the taking on of power or other responsibilities, as in “the assumption of command.”
Probably the most common meaning of assumption in use today is for indicating a supposition, an estimate, a conjecture—that is, something taken for granted. And as any schoolkid knows, presuming to assume can be dangerous, leading us to make, as the saying goes, “an ASS of U and ME!”

Other words for assumption

Other words from assumption

  • mis·as·sump·tion, noun
  • non·as·sump·tion, noun
  • o·ver·as·sump·tion, noun
  • pre·as·sump·tion, noun
  • re·as·sump·tion, noun
  • self-as·sump·tion, noun
  • su·per·as·sump·tion, noun

Words that may be confused with assumption Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use assumption in a sentence

  • It began with certain postulates, or assumptions, to a great extent unconscious, of the conditions to which it applied.

  • But for the most part property, contract and the coercive state were fundamental assumptions with the classicists.

  • She remembered the many scenes in which her spirit had been humiliated by haughty assumptions.

  • Rather may it be said, they hate counterfeits and are indignant at the assumptions of apostate Christendom.

    Gospel Philosophy | J. H. Ward
  • Their philosophy was based on assumptions and speculations, and therefore was worthless, since they settled nothing.

British Dictionary definitions for assumption (1 of 2)


/ (əˈsʌmpʃən) /

  1. the act of taking something for granted or something that is taken for granted

  2. an assuming of power or possession of something

  1. arrogance; presumption

  2. logic a statement that is used as the premise of a particular argument but may not be otherwise accepted: Compare axiom (def. 4)

Origin of assumption

C13: from Latin assūmptiō a taking up, from assūmere to assume

Derived forms of assumption

  • assumptive, adjective
  • assumptively, adverb

British Dictionary definitions for Assumption (2 of 2)


/ (əˈsʌmpʃən) /

  1. the taking up of the Virgin Mary (body and soul) into heaven when her earthly life was ended

  2. the feast commemorating this, celebrated by Roman Catholics on Aug 15

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012