Synonyms of supposition

supposition

noun

ˌsə-pə-ˈzi-shən 

1

as in hypothesis

an idea that is the starting point for making a case or conducting an investigation

my supposition is that this grape variety, which flourishes in southern France, should do equally well here, given the similar climate

Synonyms & Similar Words

• hypothesis
• theory
• thesis
• proposition
• premise
• assumption
• suggestion
• guess
• inference
• impression
• conjecture
• presumption
• hunch
• speculation
• suspicion
• theorem
• proposal
• presupposition
• generalization
• notion
• surmise
• concept
• conception
• concession
• guesswork
• construct
• abstraction
• feeling
• proffer
• inkling

Antonyms & Near Antonyms

• fact
• knowledge
• certainty
• assurance

2

as in guess

an opinion or judgment based on little or no evidence

it's pure supposition on your part that there's something illegal going on next door

Synonyms & Similar Words

• guess
• conjecture
• theory
• hypothesis
• surmise
• guessing
• hunch
• speculation
• hypothetical
• thesis
• belief
• shot in the dark
• intuition
• guesswork
• shot
• dead reckoning
• faith

3

as in assumption

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

worthless genetic research that was based on the erroneous supposition that acquired characteristics can be passed on to offspring

Synonyms & Similar Words

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

Example Sentences

Recent Examples of supposition

The supposition is the equivalent of green tea giant Bigelow taking Coca-Cola to court for its pour dominance in McDonald’s restaurants. — John Tamny, Forbes.com, 16 Apr. 2026

Zlotnikov wrote that the condition was likely caused by a mutation that had occurred very early in embryonic development, a supposition that was confirmed decades later by genetic analysis. — Jerome Groopman, New Yorker, 6 Apr. 2026

The past eight months have exposed both suppositions. — Liam Twomey, New York Times, 11 Mar. 2026

As Jackie herself once reminded John, a Kennedy has no choice but to accept that the press and public will speculate, interpret, exaggerate, and invent notions about them based on their own suppositions. — Rafaela Bassili, Vulture, 27 Feb. 2026