verb as·sume \ ə-ˈsüm \
|Updated on: 11 Jul 2018

Definition of assume

assumed; assuming
1 a : to take to or upon oneself : undertake
  • assume responsibility
b : to place oneself in
  • assume a position
2 : seize, usurp
  • assume control
3 : to pretend to have or be : feign
  • assumed an air of confidence in spite of her nervousness
4 : to take as granted or true : suppose
  • I assume he'll be there.
5 : to take over (the debts of another) as one's own
6 : put on, don
  • Mrs. Fairfax assumed her best black satin gown, her gloves, and her gold watch.
  • —Charlotte Brontë
7 a : to take up or in : receive
b : to take into partnership, employment, or use


play \-ˌsü-mə-ˈbi-lə-tē\ noun


play \-ˈsü-mə-bəl\ adjective


play \-blē\ adverb

Examples of assume in a Sentence

  1. I assumed he was coming, so I was surprised when he didn't show up.

  2. She assumed from his expression that he was confused.

  3. We'll be arriving around noon. That's assuming that our flight is on time.

  4. The king assumed the throne when he was very young.

  5. Under certain conditions, the chemical will assume the appearance of ice.

Recent Examples of assume from the Web

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

The Difference Between assume and presume

Assume and presume both mean "to take something for granted" or "to take something as true," but the words differ in the degree of confidence the person assuming or presuming has. Presume is used when someone is making an informed guess based on reasonable evidence. Assume is used when the guess is based on little or no evidence.

Presume functions a little differently in the legal catchphrase "presumed innocent until proven guilty." That sense of presume is separately defined as "to suppose to be true without proof." It is based on the fact that legal systems grant a defendant the presumption of innocence, thereby placing the burden of proof on the prosecution.

Origin and Etymology of assume

Middle English, from Latin assumere, from ad- + sumere to take — more at consume

Synonym Discussion of assume

assume, affect, pretend, simulate, feign, counterfeit, sham mean to put on a false or deceptive appearance. assume often implies a justifiable motive rather than an intent to deceive.
    • assumed an air of cheerfulness around the patients
affect implies making a false show of possessing, using, or feeling.
    • affected an interest in art
pretend implies an overt and sustained false appearance.
    • pretended that nothing had happened
simulate suggests a close imitation of the appearance of something.
    • cosmetics that simulate a suntan
feign implies more artful invention than pretend, less specific mimicry than simulate.
    • feigned sickness
counterfeit implies achieving the highest degree of verisimilitude of any of these words.
    • an actor counterfeiting drunkenness
sham implies an obvious falseness that fools only the gullible.
    • shammed a most unconvincing limp

ASSUME Defined for English Language Learners


Definition of assume for English Language Learners

  • : to think that something is true or probably true without knowing that it is true

  • : to begin (a role, duty, etc.) as a job or responsibility

  • : to take or begin to have (power, control, etc.) in a job or situation

ASSUME Defined for Kids


verb as·sume \ ə-ˈsüm \

Definition of assume for Students

assumed; assuming
1 : to begin to take on or perform
  • assume responsibility
  • assumed the presidency
2 : to take or begin to have
  • The problem assumes greater importance now.
3 : to pretend to have or be
  • We both assumed an air of weary worldliness …
  • —Richard Peck, A Long Way From Chicago
4 : to accept as true
  • I assume you're right.

Law Dictionary


transitive verb as·sume

legal Definition of assume

assumed; assuming
1 : to voluntarily take upon oneself
  • assume a risk
2 : to take over (the debts or obligations of another) as one's own
  • assume a mortgage

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