assume

UK: /əˈsjuːm/ US: /əˈsum/ ,(ə so̅o̅m′)

Inflections of 'assume' (v): (⇒ conjugate)

assumes

v 3rd person singular

assuming

v pres p

assumed

v past

assumed

v past p

WordReference Random House Learner's Dictionary of American English © 2025

as•sume /əˈsum/   v. [~ + object] , -sumed, -sum•ing. 

1. to take for granted without proof; suppose:
   to assume that everyone wants peace.
2. to take upon oneself:
   to assume responsibility.
3. to take over the duties or responsibilities of:
   to assume the office of treasurer.
4. to pretend to have or be;
   feign:
   to assume a humble manner.

as•sump•tion /əˈsʌmpʃən/  n. [countable* uncountable] See -sum-.

WordReference Random House Unabridged Dictionary of American English © 2025

as•sume  (ə so̅o̅m′), v.t., -sumed, -sum•ing. 

1. to take for granted or without proof;
   suppose;
   postulate;
   posit:
   to assume that everyone wants peace.
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.

v.i. 

10. to take something for granted;
    presume.

• Latin assūmere to take to, adopt, equivalent. to as- as- + sūmere to take up; see consume
• Anglo-French assumer)
• late Middle English (1400–50

as•sum′er, n. 
Synonyms

• 1. presuppose.
• 6. See pretend. 

Collins Concise English Dictionary © HarperCollins Publishers::

assume / əˈsjuːm/ verb (transitive)

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

Etymology: 15th Century: from Latin assūmere to take up, from sūmere to take up, from sub- + emere to take

asˈsumable adjective

asˈsumer noun