supposition

noun

sup·​po·​si·​tion ˌsə-pə-ˈzi-shən 

1

: something that is supposed : hypothesis

2

: the act of supposing

suppositional

ˌsə-pə-ˈzi-sh(ə-)nəl 

adjective

Synonyms of supposition

• hypothesis
• theory
• thesis
• proposition

Examples of supposition in a Sentence

a supposition that proved correct

This is just idle supposition.

Recent Examples on the Web

While the Red Sox reallocated some of the Devers money toward signing Roman Anthony to an eight-year, $130 million contract extension and Ranger Suárez to a five-year, $130 million deal, the original supposition was that the club would use the Devers money to re-sign Bregman. —Jen McCaffrey, New York Times, 15 Feb. 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

Both Ripa and Consuelos rejected the supposition, with Ripa admitting that the only evening during which Consuelos looks presentable during the holidays is Christmas Eve. —Joey Nolfi, Entertainment Weekly, 21 Nov. 2025

Word History

Etymology

Middle English supposicioun, from Anglo-French supposicion, from Late Latin supposition-, suppositio, from Latin, act of placing beneath, from supponere

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing supposition

• on the supposition that

Rhymes for supposition

• abolition
• acquisition
• admonition
• ammunition
• apparition
• apposition
• coalition
• competition
• composition
• definition
• deglutition
• demolition

Kids Definition

supposition

noun

sup·​po·​si·​tion ˌsəp-ə-ˈzish-ən 

1

: something that is supposed

2

: the act of supposing

suppositional

-ˈzish-nəl 

-ən-ᵊl

adjective