assume

American  

[uh-soom] / əˈsum /

verb (used with object)

assumes, present (3rd person singular) assumed, past participle, past assuming present participle

1. to take for granted or without proof.

   to assume that everyone wants peace.

   Synonyms:

   posit, postulate, presuppose, suppose

2. to take upon oneself; undertake.

   to assume an obligation.

3. to take over the duties or responsibilities of.

   to assume the office of treasurer.

4. to take on (a particular character, quality, mode of life, etc.); adopt.

   He assumed the style of an aggressive go-getter.

5. to take on; be invested or endowed with.

   The situation assumed a threatening character.

6. to pretend to have or be; feign.

   to assume a humble manner.

7. to appropriate or arrogate; seize; usurp.

   to assume a right to oneself; to assume control.

8. to take upon oneself (the debts or obligations of another).

9. Archaic. to take into relation or association; adopt.

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verb (used without object)

assumes, present (3rd person singular) assumed, past participle, past assuming present participle

1. to take something for granted; presume.

assume British  

/ əˈsjuːm /

verb

1. (may take a clause as object) to take for granted; accept without proof; suppose

   to assume that someone is sane

2. to take upon oneself; undertake or take on or over (a position, responsibility, etc)

   to assume office

3. to pretend to; feign

   he assumed indifference, although the news affected him deeply

4. to take or put on; adopt

   the problem assumed gigantic proportions

5. to appropriate or usurp (power, control, etc); arrogate

   the revolutionaries assumed control of the city

6. Christianity (of God) to take up (the soul of a believer) into heaven

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Usage

What's the difference between assume and presume? Assume and presume have very similar meanings—they both mean to suppose that something is true without being able to confirm it. Assume, however, usually implies that the conclusion reached by the person doing the assuming is not based on much. Presume, on the other hand, often implies that the conclusion is based on something a bit stronger, such as some evidence or past situations in which the same thing happened. For example, you might presume that someone will be attending a meeting because they always attend and you have no reason to think they won’t be there. The word assume could also be used in this scenario, but it’s most likely to be used in situations in which there was less of a reason to have come to a certain conclusion. For example, you might assume something about someone you’ve just met based only on how they look (which is never a good idea). A good way to remember this difference in how the two words are used is that the prefix pre- in presume means “before”—when you presume things, you’re often basing that presumption on something that has happened before. As for assume, well, we’ll just assume you know a good way of remembering how it’s used. Assume and presume also have a few meanings that don’t overlap. Assume can mean to take on, adopt, or be endowed with something, as in I don’t want to assume any new responsibilities. Presume can mean to undertake or do something without permission or justification, as in I don’t presume to speak for the entire class. Here are examples of assume and presume used correctly in a sentence. Example: I assumed you knew what you were doing when you volunteered to bake the cake, but apparently I shouldn’t have. Example: I presumed, based on your resume, that you knew how to work with this software. Want to learn more? Read the full breakdown of the difference between assume and presume.

Synonym Usage

See pretend.

Other Word Forms

Derived Forms

• preassume
  verb (used with object)
• reassume
  verb (used with object)
• assumer
  noun
• overassume
  verb (used with object)
• assumable
  adjective

Conjugated Forms

Present

• has assumed
  perfect 3rd person singular
• have assumed
  perfect
• is assuming
  progressive 3rd person singular
• are assuming
  progressive
• have been assuming
  perfect progressive
• am assuming
  progressive 1st person singular
• has been assuming
  perfect progressive 3rd person singular
• assumes
  singular 3rd person
• assuming
  participle

Past

• had assumed
  perfect
• were assuming
  progressive plural
• assumed
  simple
• had been assuming
  perfect progressive
• was assuming
  progressive singular
• assumed
  participle

Future

• will assume
  simple
• will have assumed
  perfect
• will have been assuming
  perfect progressive
• will be assuming
  progressive

Etymology

Origin of assume

First recorded in 1400–50; late Middle English (from Anglo-French assumer ), from Latin assūmere “to take to, adopt,” equivalent to as- “toward” + sūmere “to take up”; see as-, consume

Explanation

Assume isn't only used to mean "accept as truth without checking"; it also means "take on the form of." It might be safer if you don't assume that the vampire standing in front of you isn't merely a person assuming that form. Assume always has the sense of taking on something. It may be the belief in the appearance of truth: Your mother probably assumes you do your homework right after school. It may be another form or identity: Superman assumes the identity of a city reporter. Or, it might be a physical space: If you get nervous while driving, your dad might assume control of the car.

Example Sentences

Mark McDonough, a managing partner of consultancy Assume Loans, found instances in publicly available documents of homeowners who repeatedly claimed the subsidy.

From The Wall Street Journal • May 3, 2026

Assume a similar valuation now and each share could trade around $25 based on about 400 million shares outstanding.

From Barron's • Apr. 27, 2026

Assume minimum payments are about 2% of each card’s balance:

From Salon • Jan. 26, 2025

Assume that the billiard is perfect: the walls are perfectly bouncy, there are no other objects on the table, the motion of the ball is frictionless, and so on.

From Science Daily • Apr. 11, 2024

Assume for a moment that the death penalty Is a deterrent.

From "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything" by Steven D. Levitt

Related Words

• accept
• conclude
• consider
• estimate
• expect
• guess
• infer
• presume
• speculate
• suspect
• think
• understand