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

• 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

The report did not provide evidence to support the state’s assertion. —Margaret Coker, ProPublica, 24 Sep. 2025

This assertion, though not grounded in any definitive scriptural timeline, resonated widely, particularly among evangelical TikTok users. —Theo Burman, MSNBC Newsweek, 23 Sep. 2025

Everything hinges, however, on the assertion that bondpeople were constant capital, which appears five times within the first fifty pages of the work. —Literary Hub, 22 Sep. 2025

On Monday evening, the FDA released its note to doctors about a possible link between acetaminophen during pregnancy and autism, which was more measured than the president's assertions. —Mary Kekatos, ABC News, 22 Sep. 2025

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
• overexertion
• reassertion

Kids Definition

assertion

noun

as·​ser·​tion ə-ˈsər-shən 

a-

: the act of asserting

also : something asserted : declaration