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

The Washington Examiner has reached out to Fox News for comment on Freedman’s assertion. — Molly Parks, The Washington Examiner, 4 Sep. 2026

Issacharoff did not identify a source or time period for his assertion that births have exceeded deaths. — Seth Abramovitch, HollywoodReporter, 4 Sep. 2026

The commission said that no evidence was presented during the regulatory proceedings to support those assertions. — Alex Kuffner, The Providence Journal, 3 Sep. 2026

Yet, on so many fronts, Trump’s assertion of that power appears to be backfiring. — Ishaan Tharoor, New Yorker, 3 Sep. 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