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 government denies the assertion by Imamoglu and the CHP that the case against him is politically driven and says that Turkey’s courts are independent. —Reuters 17 Hr Ago, CNN Money, 11 Nov. 2025

His assertion that there are no examples of private sector employees performing better and for less cost than city employees is laughable. —U T Readers, San Diego Union-Tribune, 11 Nov. 2025

But with legal developments, rushing to publish can lead to out-of-context assertions or worse. —Michael McCann, Sportico.com, 11 Nov. 2025

At least, that’s the assertion of the National Republican Congressional Committee, the campaign arm of the House Republicans. —John Cassidy, New Yorker, 10 Nov. 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