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 officials from each of the two states rejected Florida's assertions. —Melissa Quinn, CBS News, 26 May 2026

There is an element of truth to the assertion, because referees would much rather upgrade a caution to a dismissal than the reverse. —Graham Scott, New York Times, 24 May 2026

In the camp that says computer science as a major is doomed, there is an interesting assertion of what the next best choice alternative consists of. —Lance Eliot, Forbes.com, 22 May 2026

Hernandez declined to comment, but Chang didn’t dispute the assertion that DSA is seeking to gain power. —Sandra McDonald, Los Angeles Times, 20 May 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