Assertion

Research

A confident claim presented as true, forming the basic building block of an argument; must be substantiated with evidence, not merely stated.

Sources

1. Merriam-Webster — assertion merriam-webster.com accessed 23 September 2026

Merriam-Webster defines it simply as “the act of asserting or something that is asserted” — an insistent affirming, or a declaration that something is the case. First recorded in the fifteenth century, from assert. Its near neighbours in the dictionary are telling: declaration, claim, insistence, allegation. Every one of them names a statement made, not a statement supported — which is exactly why “assertion” is the word used when an argument has skipped a step.

Merriam-Webster is cited as the dictionary of record: where an entry defines a word rather than a position, a dictionary is the primary source for it. The research usage above is this lexicon’s own.

Related terms

• Abbreviation
• Abstract
• Abstraction
• Academic Database
• Analysis
• Annotation

From the AJG lexicon archive (July 2026).