assertion

English

Etymology

From Middle English assercioun, from Latin assertiō.^[1] By surface analysis, assert +‎ -ion.

Pronunciation

(Received Pronunciation) IPA^(key): /əˈsɜːʃən/
(General American) IPA^(key): /əˈsɜɹʃən/, [əˈsɝʃn̩]
Audio (US): (file)
Audio (UK): (file)

Rhymes: -ɜː(ɹ)ʃən

Noun

assertion (countable and uncountable, plural assertions)

The act of asserting; positive declaration or averment.
- 1869, Alfred Russel Wallace, The Malay Archipelago, volume II, London: Macmillan and Co., page 247:
  "Do tell us the real name of your country, and then when you are gone we shall know how to talk about you." To this luminous argument and remonstrance I could oppose nothing but assertion, and the whole party remained firmly convinced that I was for some reason or other deceiving them.
Something which is asserted; a declaration; a statement asserted.
Synonym: contention

You're a man of strong assertions!
- 2007 January 26, Ruth M. J. Byrne, The Rational Imagination: How People Create Alternatives to Reality‎^[1], MIT Press, →ISBN, page 140:
  Suppose you are given the semifactual assertion, "even if Nora had liked mathematics then she would have became^[sic] a scientist" and then you find out that Nora did in fact become a scientist.
A statement or declaration which lacks support or evidence.
That's just a bare assertion.
- 2022 August 24, Philip Haigh, “Network News: Union slams Avanti West Coast: 'lie' as services slashed”, in RAIL, number 964, page 6:
  Drivers' union ASLEF bluntly rebuffed the claim of unofficial action, calling it a lie. And Avanti West Coast was unable to provide any proof for its assertion, when questioned by RAIL.
- 2026 February 27, Jennifer Hansler, Natasha Bertrand, Kylie Atwood, Zachary Cohen, “Trump has claimed Iran is building missiles that could soon hit the US. Sources say that’s not backed up by US intelligence.”, in CNN‎^[2], archived from the original on 3 March 2026:
  However, that assertion is not backed up by US intelligence, sources told CNN. […] That claim came despite the Trump administration’s repeated assertions that the US had “obliterated” Iran’s nuclear program in military strikes last year.
Maintenance; vindication.
the assertion of one's rights or prerogatives
(programming) A statement in a program asserting a condition expected to be true at a particular point, used in debugging.
- 2006, Srikanth Vijayaraghavan, Meyyappan Ramanathan, A Practical Guide for SystemVerilog Assertions, page 284:
  The user should be absolutely confident that the error issued is a real design error. In other words, a user should be confident that his assertion code is correct and that the assertion failure is not a false condition.
(finance) The set of information that the statement preparer is providing in a financial statement audit.