English Reference
noun

obsession

n.
US /əbˈsɛʃən/ UK /ɒbsˈɛʃən/ ob·ses·sion UK spelling obsession's, obsession's

  1. 01 B2 Upper Intermediate

    a state where you think about something or someone all the time and cannot stop.

    a persistent and disturbing preoccupation with an often unreasonable idea or feeling. Often used uncountably to describe the psychological state.

    Simple

    His obsession with fitness means he spends four hours at the gym every single day.

    In context

    The public's obsession with the celebrity's private life has led to a complete breakdown of her personal boundaries and mental health.

    Usage

    Commonly follows the pattern 'obsession with [something]'.

    Pitfall
    He has an obsession for classic cars. He has an obsession with classic cars.

    The noun 'obsession' almost always takes the preposition 'with' when identifying the object of interest.

    indifferencedisinterest
  2. 02 B2 Upper Intermediate

    the specific thing or person that you are obsessed with.

    a specific activity, person, or entity that inspires a compulsive fixation. Countable in this sense.

    Simple

    Collecting rare stamps became a lifelong obsession for him.

    In context

    What started as a casual interest in local history eventually transformed into a consuming obsession that dictated his travel plans for a decade.

  3. 03 C2 Proficiency FormalTechnical Religion

    the belief that an evil spirit is controlling or influencing someone's mind.

    the state of being influenced or beset by an evil spirit, distinguished from 'possession' where the spirit inhabits the body.

    Simple

    The old texts described a case of obsession where the victim heard voices from the shadows.

    In context

    Theological scholars distinguish between possession, where the entity resides within, and obsession, where the external influence torments the individual's psyche.

King Charles is on the throne, there’s anxiety around the power-brokers of Whitehall, and an age of deep political division and conspiracy obsession is under way.

The Guardian· 13 Aug 2026

Turfgrass lawns, for example, a particular American obsession , requires regular mowing, fertilizing and watering, increasing greenhouse gas emissions and water use.

The Conversation· 3 Aug 2026

From Latin obsessio (“a besieging”), from obsidere (“to besiege”); see obsess. Equivalent to obsess + -ion.

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

This entry
Level C1 · Advanced
Frequency Frequent
Updated