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 Clippers’ assertion came after ESPN reported two key points regarding the NBA’s ongoing investigation into how Kawhi Leonard was compensated during his tenure with the team. — Michael McCann, Sportico.com, 20 Aug. 2026

Culture Minister Isaac Tchiakpé rejected RSF’s assertion that the filmmakers had received authorization from his ministry to carry out the documentary shoot. — ABC News, 20 Aug. 2026

Many homeowners pushed back against the assertion that the density would result in more affordable housing. — Luis Melecio-Zambrano, Mercury News, 19 Aug. 2026

Several days later, two lawyers issued a statement disputing that assertion. — Emily R. Condon, USA Today, 19 Aug. 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