Synonyms of assumption

assumption

noun

ə-ˈsəm(p)-shən 

1

as in theory

something taken as being true or factual and used as a starting point for a course of action or reasoning

the widespread assumption that violent entertainment leads to violent behavior in children

your argument is faulty because it's based on erroneous assumptions

Synonyms & Similar Words

• theory
• premise
• hypothesis
• belief
• presumption
• presupposition
• hypothetical
• given
• postulate
• supposition
• if
• principle
• assertion
• proposition
• axiom
• inference
• basis
• doctrine
• thesis
• conclusion
• truism
• rule
• law
• tenet
• dogma
• gospel
• precept
• declaration
• foundation
• standard
• verity
• deduction
• affirmation
• canon
• dictum
• ground
• avouchment
• ipse dixit

2

as in arrogance

an exaggerated sense of one's importance that shows itself in the making of excessive or unjustified claims

his air of assumption tended to put people off rather quickly

Synonyms & Similar Words

• arrogance
• superiority
• attitude
• consequence
• disdain
• pretense
• pretension
• bumptiousness
• superciliousness
• haughtiness
• presumptuousness
• imperiousness
• peremptoriness
• loftiness
• high horse
• toploftiness
• self-importance
• hauteur
• pomposity
• self-consequence
• pompousness
• pretentiousness
• pridefulness
• lordliness
• masterfulness
• dominance
• huffiness
• vanity
• condescension
• inflation
• pride
• snobbery
• snobbishness
• scorn
• bossiness
• high-handedness
• snobbism
• authoritativeness
• bravado
• side
• self-assertion
• smugness
• snootiness
• brag
• chest-thumping
• triumphalism
• boastfulness
• egoism
• sauciness
• cheekiness
• self-assumption
• conceit
• self-opinion
• swagger
• bowwow
• cockiness
• impudence
• self-conceit
• self-satisfaction
• braggadocio
• self-complacency
• complacence
• self-content
• egotism
• vainglory
• vaingloriousness
• strut
• self-contentment
• impertinence
• swelled head
• self-centeredness
• superiority complex
• cheek
• bombast
• self-partiality

Antonyms & Near Antonyms

• humility
• modesty
• unpretentiousness
• shyness
• timidity
• bashfulness
• diffidence
• demureness
• unassumingness
• passivity
• self-doubt
• submissiveness
• reserve
• meekness
• passiveness
• lowliness
• timidness
• retiringness
• quietness
• self-distrust
• mousiness
• reservedness

Example Sentences

Recent Examples of assumption

In a recent Nature study, Terral and Renata Batista-Brito, who runs the lab, report a population of cortical cells that challenges that assumption. — Jacek Krywko, ArsTechnica, 18 Sep. 2026

As a result, business leaders who continue to rely on historical assumptions may be underestimating exposures that could have significant financial and operational consequences. — Patty Templeton-Jones, Forbes.com, 18 Sep. 2026

The inspector general found that explanation wasn’t always clear and that the person approving travel often operated under the assumption that an executive had requested it. — Los Angeles Times, 17 Sep. 2026

But that miscalculation was, itself, premised on the unexamined assumption that a K-12 public education should be essentially vocational and therefore—almost by definition—aligned with corporate interests. — Jessica Winter, New Yorker, 17 Sep. 2026