# assert

> English word · Verb · IPA /əˈsɜːt/ · frequency rank #12,544

## Definitions
1. To declare with assurance or plainly and strongly; to state positively.
2. To use or exercise and thereby prove the existence of.
3. To maintain or defend, as a cause or a claim, by words or measures; to vindicate a claim or title to.
4. To insist on the legitimacy of one's rights, opinion, etc; not to allow oneself to be dismissed; to ensure that one is taken into consideration; to make oneself respected; to be assertive. See assert oneself.
5. To declare that a condition or expression must be true at a certain point in the source code (in some cases causing the program to fail if it is not, as a safeguard).
6. To set a signal on a line using a voltage or electric current.

## Etymology
From Latin assertus, perfect passive participle of asserō (“declare someone free or a slave by laying hands upon him; hence free from, protect, defend; lay claim to, assert, declare”), from ad (“to”) + serō (“join, range in a row”).

## Easily confused with
- **asset** (https://plainspell.com/en/vs/assert-vs-asset)
- **asses** (https://plainspell.com/en/vs/assert-vs-asses)
- **avert** (https://plainspell.com/en/vs/assert-vs-avert)
- **aster** (https://plainspell.com/en/vs/assert-vs-aster)
- **assets** (https://plainspell.com/en/vs/assert-vs-assets)
- **assist** (https://plainspell.com/en/vs/assert-vs-assist)
- **assess** (https://plainspell.com/en/vs/assert-vs-assess)
- **assure** (https://plainspell.com/en/vs/assert-vs-assure)
- **asserted** (https://plainspell.com/en/vs/assert-vs-asserted)
- **alert** (https://plainspell.com/en/vs/alert-vs-assert)
- **Asher** (https://plainspell.com/en/vs/asher-vs-assert)
- **assed** (https://plainspell.com/en/vs/assed-vs-assert)
- **aspect** (https://plainspell.com/en/vs/aspect-vs-assert)
- **Albert** (https://plainspell.com/en/vs/albert-vs-assert)
- **absent** (https://plainspell.com/en/vs/absent-vs-assert)
- **advert** (https://plainspell.com/en/vs/advert-vs-assert)
- **ascent** (https://plainspell.com/en/vs/ascent-vs-assert)
- **assent** (https://plainspell.com/en/vs/assent-vs-assert)

## Common misspellings (7)
`asert`, `asesrt`, `asserrt`, `assertt`, `assetr`, `assret`, `sasert`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/assert