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

Wilson also accused the trio of embezzlement; the producers deny the assertions, including the allegation about the locked room fiasco. —Natalie Oganesyan, Deadline, 23 Nov. 2025

Kyiv, however, has disputed Moscow’s assertions of sweeping battlefield gains, insisting Russian advances remain limited. —Matthew Robinson, MSNBC Newsweek, 21 Nov. 2025

Alyssa Farah Griffin fired back at The View audience for flaming her during a tense debate at the Hot Topics table about Michelle Obama's recent assertion that America isn't ready for a female president. —Joey Nolfi, Entertainment Weekly, 17 Nov. 2025

The documents do not substantiate these assertions, and the White House has denied them. —Eva Roytburg, Fortune, 14 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