English Reference
noun

dependency

n.
US /dɪˈpɛndənsi/ UK /dɪpˈɛndənsi/ de·pen·den·cy UK spelling dependencies

  1. 01 B2 Upper Intermediate

    a situation where you need someone or something to help you or to work correctly.

    the state of being dependent on or controlled by someone or something else.

    Simple

    The small island's dependency on tourism makes it vulnerable during the winter months.

    In context

    The economic dependency of the satellite states on the central government created a fragile system that collapsed once subsidies were withdrawn.

    reliancesubordination
  2. 02 B2 Upper Intermediate Medicine

    a physical or mental need for a drug, alcohol, or a specific habit.

    a state of physiological or psychological need for a habit-forming substance.

    Simple

    He sought medical help to overcome his dependency on sleeping pills.

    In context

    Long-term chemical dependency often requires a combination of clinical detoxification and sustained psychological support to prevent relapse.

  3. 03 C1 Advanced Technical Computing

    a piece of software or a file that another program needs in order to run.

    a software component, library, or module that is required by another piece of software to function correctly.

    Simple

    Before you can install the game, you must download a few dependencies first.

    In context

    The build failed because the compiler could not resolve a version conflict between two shared dependencies in the project manifest.

    Usage

    Often used in the plural when referring to a list of required libraries.

  4. 04 C1 Advanced Formal

    a country or area that is controlled by another, more powerful country.

    a territory or colony that is subject to the jurisdiction of an external power but not formally annexed.

    Simple

    The region remains a British overseas dependency with its own local government.

    In context

    The constitutional status of the dependency was debated in the international court, as the local population sought greater self-determination.

    sovereign state

Long-term use of the drugs can also result in dependency; users find they rely on it for any social situation.

BBC News· 18 Aug 2026

Every week, Annette Deao, a drug dependency counselor, sits in the county jail and offers incarcerated people in rural Ohio a chance at recovery.

The Guardian· 15 Aug 2026

From dependent + -cy or dependence + -y or depend + -ency.

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

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated