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

But authorities boast that the state has lately become a model for reducing mob mayhem — an assertion that many find suspect. — Los Angeles Times, 26 July 2026

In the film, however, Odysseus’s falsehoods have dire consequences, an apparent reflection of the biblical assertion that false witness is a sin. — Luis Parrales, The Atlantic, 26 July 2026

Mexican health authorities, meanwhile, have also said there has not yet been ample evidence to support the FDA's assertion that the outbreak originated over the border, as reported by USA TODAY. — Sara Moniuszko, USA Today, 24 July 2026

Attorney Taylor Meehan, representing Tennessee election officials, rejected the assertion of racially discriminatory motivations. — ABC News, 23 July 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