assertion

noun

as·​ser·​tion ə-ˈsər-shən 

a-

: the act of asserting or something that is asserted: such as

a

: insistent and positive affirming, maintaining, or defending (as of a right or attribute)

an assertion of ownership/innocence

b

: a declaration that something is the case

He presented no evidence to support his assertions.

Synonyms of assertion

• declaration
• claim
• insistence
• allegation

Examples of assertion in a Sentence

the assertion that all men have certain unalienable rights is set forth in the Declaration of Independence

made the unlikely assertion that gravity affects light

Recent Examples on the Web

Here, the architecture distributes the congregation into a half circle, gathering them around the matter of their faith as a question rather than as an assertion. — Kristian Vistrup Madsen, Artforum, 1 Nov. 2026

Reporting by Drilled and ProPublica did not contradict that assertion. — Katie Worth, ProPublica, 30 Oct. 2026

But records obtained through a public information request cast doubt on that assertion. — Mark Betancourt, NPR, 30 Oct. 2026

Federal prosecutors also have said voters won't be disenfranchised by delaying the tabulation of their ballots while their citizenship is checked — an assertion disputed by county election officials. — ABC News, 29 Oct. 2026

Word History

Etymology

see assert

First Known Use

15th century, in the meaning defined above

Phrases Containing assertion

• self-assertion

Rhymes for assertion

• cistercian
• coercion
• desertion
• exertion
• insertion
• mercian
• tertian
• overexertion
• reassertion

Kids Definition

assertion

noun

as·​ser·​tion ə-ˈsər-shən 

a-

: the act of asserting

also : something asserted : declaration