as·​sump·​tion | \ ə-ˈsəm(p)-shən How to pronounce assumption (audio) \

Definition of assumption

1 : a taking to or upon oneself the assumption of a new position
2 : the act of laying claim to or taking possession of something the assumption of power
3a : an assuming that something is true a mistaken assumption
b : a fact or statement (such as a proposition, axiom (see axiom sense 2), postulate, or notion) taken for granted
4a : the taking up of a person into heaven
b capitalized : August 15 observed in commemoration of the Assumption of the Virgin Mary
5 : the taking over of another's debts

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Examples of assumption in a Sentence

I made the assumption that he was coming, so I was surprised when he didn't show up. He will come home tomorrow. At least, that's my assumption. Many scientific assumptions about Mars were wrong. I'm telling you our arrival time on the assumption that you will check to see whether or not our flight is on time before you come to the airport. Her plan is based on the underlying assumption that the economy will improve in the near future. her assumption of the presidency the buyer's assumption of debt
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Recent Examples on the Web Boeing and regulators had approved the design under the assumption that flight crews could recognize and override a malfunction of the system within a few seconds. Alan Levin, Fortune, "Boeing crashes were the “horrific culmination” of multiple mistakes, House report says," 16 Sep. 2020 These recommendations were put together with the assumption that applicants would have average credit or above. Taylor Medine, USA TODAY, "Chase's new credit card has big-time benefits without an annual fee," 15 Sep. 2020 Our assumption is it’s an acute respiratory distress syndrome. al, "Tall tales and conspiracy theories: Alabama experts battle coronavirus misinformation," 6 Sep. 2020 Multiple trials are proceeding under the assumption that some won’t work, or that some vaccines will work better in certain demographic populations than others. Jeremy Olson, Star Tribune, "HealthPartners recruiting Minnesotans for COVID-19 vaccine trial," 2 Sep. 2020 Federal relief programs were designed to last a few months, under the assumption the recovery would be underway. Dallas News, "A reckoning looms for Dallas-Fort Worth small businesses as pandemic stretches on," 16 Aug. 2020 The Miami Hurricanes continue to practice in fall camp under the assumption the ACC plan of playing its 10-plus-1 schedule in the fall will be upheld. David Furones,, "How would a postponed college football season impact Miami Hurricanes players with eligibility, NFL draft?," 11 Aug. 2020 Lawmakers initially planned to phase out the additional $600 stipend under the assumption that coronavirus infections would decline, but case numbers are still high around the nation with 51,185 new cases reported in the United States on Wednesday. Connor Sanders, The Salt Lake Tribune, "State opens rental aid program to Utahns receiving jobless benefits," 5 Aug. 2020 The model also accounted for income distribution, on the assumption that wealthier households would be less likely to migrate. Amanda Shendruk, Quartz, "It’s time to prepare cities for people uprooted by climate change," 1 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'assumption.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of assumption

13th century, in the meaning defined at sense 4a

History and Etymology for assumption

Middle English, from Late Latin assumption-, assumptio taking up, from Latin assumere — see assume

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Time Traveler for assumption

Time Traveler

The first known use of assumption was in the 13th century

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Statistics for assumption

Last Updated

20 Sep 2020

Cite this Entry

“Assumption.” Dictionary, Merriam-Webster, Accessed 24 Sep. 2020.

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More Definitions for assumption


How to pronounce assumption (audio)

English Language Learners Definition of assumption

: something that is believed to be true or probably true but that is not known to be true : something that is assumed
: the act of beginning a role, duty, etc.
: the act of taking or beginning to have power, control, etc., in a job or situation


as·​sump·​tion | \ ə-ˈsəmp-shən How to pronounce assumption (audio) \

Kids Definition of assumption

1 : the act of taking on the assumption of power
2 : something accepted as true I'm making plans on the assumption that you will be here.

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