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domain

n.
US //doʊˈmeɪn// UK //dəmˈeɪn// do·main
  1. 1 field of interest or activity (n.)
    B2 Upper Intermediate Academic

    a specific area of knowledge, interest, or activity.

    a sphere of activity, influence, or expertise; often used in academic contexts to describe a subject area.

    Example

    The professor is an expert in the domain of medieval history.

    Example

    While her early research focused on linguistics, her later work expanded into the domain of cognitive psychology and neural mapping.
  2. 2 internet address (n.)
    B1 Intermediate Computing

    a set of words used to identify a website on the internet.

    a series of alphanumeric strings separated by periods that identifies a specific location on the internet.

    Example

    You need to register a domain name before you can launch your website.

    Example

    The company decided to purchase the .com domain to ensure their brand was easily accessible to a global audience.
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  1. 3 area of control (n.)
    C1 Advanced Formal Law

    an area of land that is owned or controlled by one person or government.

    a territory over which dominion is exercised; a district or region under a particular jurisdiction.

    Example

    The king rode across his vast domain to visit the distant villages.

    Example

    The court ruled that the state had the right of eminent domain, allowing it to seize private property for public infrastructure projects.
  2. 4 mathematical input (n.)
    C1 Advanced Technical Math

    the set of all possible numbers that can be put into a mathematical function.

    the set of all possible values of an independent variable for which a function or relation is defined.

    Example

    In this equation, the domain includes all positive whole numbers.

    Example

    Students must first determine the domain of the function to identify any values that would result in an undefined output.
  3. 5 biological classification (n.)
    C2 Proficiency Technical Science

    the highest group used to classify living things.

    the highest taxonomic rank of organisms in the three-domain system, sitting above the kingdom level.

    Example

    Humans belong to the Eukarya domain because our cells have a nucleus.

    Example

    The discovery of Archaea led biologists to revise the tree of life, establishing it as a distinct domain separate from Bacteria.

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