English Reference
noun

reaction

n.
US /ɹiˈækʃən/ UK /ɹɪˈækʃən/ re·ac·tion UK spelling reaction's, reaction's

  1. 01 B1 Intermediate

    something you say, feel, or do because of something else that happened.

    a physiological or psychological response to a stimulus or event.

    Simple

    His first reaction to the news was a look of pure surprise.

    In context

    The public reaction to the proposed tax increase was overwhelmingly negative, forcing the local council to reconsider its budget priorities.

  2. 02 B2 Upper Intermediate Technical Science

    a process where two or more substances change into something new.

    a process involving the rearrangement of the molecular or ionic structure of a substance.

    Simple

    The chemical reaction caused the liquid to turn bright green.

    In context

    The catalyst was added to accelerate the reaction, ensuring that the compound reached stability before the temperature dropped.

  3. 03 B1 Intermediate Informal Computing

    an icon or emoji you use to show how you feel about a post on social media.

    a digital feedback mechanism, typically an emoji, used to express a specific sentiment toward online content.

    Simple

    She got over fifty heart reactions on her new photo.

    In context

    The platform introduced several new reactions, allowing users to express nuanced emotions beyond a simple 'like' button.

  4. 04 C1 Advanced AcademicFormal Politics

    a movement that opposes social or political change.

    opposition to political or social progress or reform; reactionary policy.

    Simple

    The new law met with strong reaction from traditional groups.

    In context

    The revolution was followed by a period of intense political reaction, as the old elite sought to dismantle the newly established democratic institutions.

Usage reactions to his work · emotional reaction · initial reaction


Inherited from Middle English reaccion, from Old French reaction, from Latin reāctiō, from the verb reagō, from re- (“again”) + agō (“to act”); more at re-, action; equivalent to react + -ion.

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

This entry
Origin Old French reaction
Level B1 · Intermediate
Frequency Common
Updated