ENGLISH
REFERENCE

assertion

n. countable
C1 Advanced Oxford US //əˈsɝʃən// UK //ɐsˈɜːʃən// as·ser·tion

n. a strong statement that something is true, even if you do not have proof yet. You use this when you want to sound confident about an idea or a fact.

n. a confident and forceful statement of fact or belief. In formal logic or programming, it refers to a predicate that a developer expects to be true at a specific point in the code.


SIMPLE

She made a bold assertion about the company's future.

CONTEXTUAL

The lawyer's assertion that the witness was lying changed the mood of the entire trial.

COMPLEX

While the author provides plenty of anecdotal evidence, the central assertion of the book remains unsupported by any peer-reviewed data or statistical analysis.

Synonyms
Origin

From Middle English assercioun, from Latin assertiō. By surface analysis, assert + -ion.

Usage

Often followed by the preposition 'that' or 'of'.

© 2026 English Reference