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

Richards and the governor’s office pushed back on false assertions that Newsom and his wife, First Partner Jennifer Siebel Newsom, were stealing money from the state through her office that same day. —Taryn Luna, Los Angeles Times, 6 Mar. 2026

This Bond-song assertion is not based on insider information, or some silly predictors’ market. —Chris Willman, Variety, 5 Mar. 2026

Democrats urged her to speak on previous assertions that Renee Nicole Macklin Good and Alex Pretti, two Minnesota residents who federal immigration officials shot, were domestic terrorists. —Faith Bugenhagen, Austin American Statesman, 5 Mar. 2026

Hours before the hearing was set to begin, the GOP-run committee released a report alleging Walz and Ellison knew about credible fraud concerns years ago and didn’t act on them, despite their assertions otherwise, purportedly costing taxpayers billions. —Danya Gainor, CNN Money, 4 Mar. 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
• overexertion
• reassertion

Kids Definition

assertion

noun

as·​ser·​tion ə-ˈsər-shən 

a-

: the act of asserting

also : something asserted : declaration