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

JeffCo says that assertion is completely inaccurate, and the males listed on those rosters were coaches, trainers, and mascots, not athletes. —Christa Swanson, CBS News, 15 June 2026

Hegel redefined the dialectic as a process of assertion, negation, and synthesis that gathers force through history. —Alex Ross, New Yorker, 15 June 2026

No matter how often Democrats and race idolaters insist that white supremacy remains America's defining force, repetition does not transform an assertion into reality. —Bobby Burack Outkick, FOXNews.com, 15 June 2026

Pattie Gonia has disputed those assertions in online videos, but declined to comment further to Fortune, citing the pending litigation. —Phil Wahba, Fortune, 15 June 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