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

Because Israel had never conceived of its attacks on Hezbollah as a war of aggression in the first place, the assertion of this right amounted to a threat to return to Lebanon for further rounds of demolition. —Graeme Wood, The Atlantic, 2 Sep. 2025

Some Reddit users made similar assertions in a July 20 r/Target thread—claiming employees had to work past closing or come in at 4am to remove prices on tags. —Dave Smith, Fortune, 2 Sep. 2025

But Trump’s assertion that IEEPA essentially gives him unlimited power to tax imports quickly drew legal challenges — at least seven cases. —Paul Wiseman, Chicago Tribune, 29 Aug. 2025

But that assertion hung over every conversation surrounding aid — and continues to do so. —Tom Bowman, NPR, 28 Aug. 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