assertion

American  

[uh-sur-shuhn] / əˈsɜr ʃən /

noun

• assertions
  plural

1. a positive statement or declaration, often without support or reason.

   a mere assertion;

   an unwarranted assertion.

   Synonyms:

   allegation, contention, claim

2. an act of asserting.

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assertion British  

/ əˈsɜːʃən /

noun

1. a positive statement, usually made without an attempt at furnishing evidence

2. the act of asserting

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Other Word Forms

Derived Forms

• misassertion
  noun
• nonassertion
  noun
• overassertion
  noun
• reassertion
  noun
• superassertion
  noun
• assertional
  adjective

Inflected Forms

Nouns

• assertions
  plural

Etymology

Origin of assertion

1375–1425; late Middle English assercion < Latin assertiōn- (stem of assertiō ). See assert, -ion

Explanation

An assertion is a declaration that's made emphatically, especially as part of an argument or as if it's to be understood as a statement of fact. To assert is to state with force. So if someone makes an assertion, they’re not just trying out an idea — they really mean it. An assertion can also be an act that seems to make a statement without words. When your dog urinates in multiple places up and down your block, he's making an assertion of his dominance (also called "marking") over his "territory."

Example Sentences

See Examples For:

assertion assertions

Leaders of a dozen newly minted Asian nations gathered there, in a powerful assertion of a new path, absent the heavy hand of the West.

From The Wall Street Journal ● Sep. 11, 2026

The city’s determination stalling the project “is based on the false assertion that the active golf course, in the middle of a residential neighborhood, is habitat for mountain lions,” he said.

From Los Angeles Times ● Aug. 22, 2026

In response to questions about whether the release supported the president’s assertion, the White House responded with a link to a social media post by U.S.

From Salon ● Aug. 21, 2026

Asked whether he would say sorry for his "disrespectful behaviour" in parliament on Tuesday, the Australian leader said: "I reject the assertion in the question."

From Barron's ● Aug. 12, 2026

One might at first be inclined to dismiss this assertion as meaningless, because the experiment is imaginary and my claim about its outcome cannot be verified.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

The Civilian Oversight Commission has said that such assertions are unfounded, and that state law and court precedent require its subpoenas to be upheld.

From Los Angeles Times ● Sep. 7, 2026

A Bilt spokesperson said Warren’s assertions were “incorrect.”

From Salon ● Sep. 1, 2026

This should not be viewed as vindictive because “the government was seeking to protect the public and confirm its prior assertions about Abrego’s criminal activity,” prosecutors wrote.

From Slate ● Aug. 23, 2026

Lawyers for Cottrell have said he "categorically disputes allegations and assertions made by The Sunday Times, which clearly fail to reflect what that publisher was told in advance of its reporting".

From BBC ● Jul. 25, 2026

Participants read assertions whose veracity was either affirmed or denied by the subsequent presentation of an assessment word.

From "The Sense of Style" by Steven Pinker

Related Words

• affirmation
• allegation
• contention
• insistence
• pronouncement