English Reference
noun

contagion

n.
US /kənˈteɪdʒən/ UK /kəntˈeɪdʒən/ con·ta·gion UK spelling contagions

  1. 01 C1 Advanced Academic

    the way that a feeling, an idea, or a way of behaving spreads quickly to other people.

    the rapid transmission of an emotional state, attitude, or social behaviour through a population. Frequently used in sociological contexts to describe collective behaviour.

    Simple

    There was a contagion of fear throughout the crowd as the sirens grew louder.

    In context

    Social media platforms can facilitate a rapid contagion of misinformation, making it difficult for authorities to provide accurate updates during a crisis.

  2. 02 C1 Advanced TechnicalAcademic Finance

    the way that a financial problem in one country or market quickly spreads to others.

    the transmission of a financial shock or economic crisis from one market or region to others. Usually implies a systemic failure where local shocks trigger global instability.

    Simple

    Economists worried that the bank's failure would cause a contagion across the whole region.

    In context

    Market analysts monitored the situation closely, fearing that the sovereign debt default in one nation would trigger a regional financial contagion.

    spilloverripple effect

Psychologists call this social contagion: the spread of emotions, behaviours and beliefs through groups.

The Guardian· 9 Aug 2026

From Middle English (late 14th century), from Old French, from Latin contāgiō (“a touching, contact, contagion”) related to contingō (“touch closely”).

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

This entry
Origin Latin contāgiō
Level C1 · Advanced
Frequency Occasional
Updated