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

• 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

This is because, despite assertions to the contrary, research, such as Dr Sandra Portocarrero’s work on undocumented entrepreneurs in California, has shown that immigrants contribute positively to the economy. —London School Of Economics, Forbes.com, 24 June 2025

Those are assertions that will be reexamined as the impact of Saturday’s U.S. bombings becomes clearer. ‘MAKE IRAN GREAT AGAIN’: Trump, who previously denied wanting to topple Iran’s regime, on Sunday seemed to encourage that idea. —Alexis Simendinger, The Hill, 23 June 2025

Despite Haliburton’s assertion, Indiana was written off as dead. —Shakeia Taylor, New York Times, 20 June 2025

In the biggest and broadest protests of his second term, millions of Americans in about 2,000 communities across the country gathered Saturday to object to his assertion of unprecedented presidential powers that opponents say violate the Constitution. —Nicole Fallert, USA Today, 17 June 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