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

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

And while it has been mentioned in this space that draft capital for Norman Powell might be one way to go for the Heat, that was based on the supposition of Tyler stepping in as a scoring leader. — Ira Winderman, Sun Sentinel, 20 Jan. 2026

Under California law, fraud must be pled with particularity, meaning there must be specifics and details in the complaint; generalizations, inferences and supposition don’t cut it. — Michael McCann, Sportico.com, 16 Jan. 2026

The nature of Tech’s loss only supports the supposition that, without Texas and Oklahoma, the Big 12 is sorely lacking in top-tier talent. — Kevin Sherrington jan. 1, Dallas Morning News, 1 Jan. 2026