English Reference
verb

assert

v.
US /əˈsɝt/ UK /ɐsˈɜːt/ as·sert UK spelling asserts

  1. 01 C1 Advanced FormalAcademic

    to say something clearly and firmly so that others know you are sure it is true.

    to state a fact or belief confidently and forcefully. Transitive — requires a direct object or a 'that' clause.

    Simple

    The lawyer continued to assert that her client was innocent despite the new evidence.

    In context

    The report asserts that the current economic downturn is a direct result of global supply chain disruptions rather than domestic policy failures.

    Usage

    Often followed by a 'that' clause or a direct noun phrase.

  2. 02 C1 Advanced Formal

    to use your power or rights so that people recognise them.

    to exercise or enforce one's authority, influence, or rights to ensure they are recognised.

    Simple

    The director had to assert his authority when the team refused to follow the new rules.

    In context

    The central bank moved to assert its independence by raising interest rates despite significant political pressure from the government.

  3. 03 C1 Advanced Formal

    to behave in a way that shows you have power and should be respected.

    to behave in a confident and forceful manner so that one's presence or opinions are taken into account.

    Simple

    You need to assert yourself in meetings if you want your ideas to be heard.

    In context

    As the youngest member of the board, she found it necessary to assert herself during the heated debates over the merger.

    Usage

    Commonly used reflexively as 'assert oneself'.

    stand up for oneself
  4. 04 C2 Proficiency Technical Computing

    to check that a specific condition is true in a computer program, or to turn on an electrical signal.

    to verify a logical condition in code or to set a signal line to a specific voltage level.

    Simple

    The program will stop if the code tries to assert a condition that is false.

    In context

    The system is designed to assert the interrupt signal as soon as the sensor detects a change in pressure.

    Usage

    In electronics, the opposite is 'deassert'.

    deassert

Given that Michigan will now have an earlier say in the voting process, some experts have speculated that the swing state could help progressives assert greater influence over the party overall.

Al Jazeera· 15 Aug 2026

Still, the mass of signatures is the latest indication of entrenched discontent in Canada towards Trump’s policies, which include a push to assert greater US influence over the entire Western Hemisphere.

Al Jazeera· 15 Aug 2026

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”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin assertus
Level C1 · Advanced
Frequency Frequent
Updated