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expand

v.
US //ɪkˈspænd// UK //ɛkspˈænd// ex·pand
  1. 1 to grow larger (v.)
    B1 Intermediate Science

    to become larger in size, amount, or volume.

    to increase in physical size, volume, or quantity. Often used as an intransitive verb to describe physical processes.

    Example

    Metals expand when they get hot and shrink when they cool down.

    Example

    The gases in the chamber expand rapidly upon ignition, driving the piston downward with significant force.
  2. 2 to increase scope (v.)
    B1 Intermediate

    to make a business or an idea cover more areas or include more things.

    to increase the extent, number, or scope of an enterprise or concept. Transitive or intransitive depending on whether the focus is the agent or the entity growing.

    Example

    The company wants to expand its business into other countries next year.

    Example

    The university decided to expand its research department to include a dedicated wing for renewable energy studies.
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  1. 3 to give more detail (v.)
    B2 Upper Intermediate Academic Formal

    to give more information about something you have already said or written.

    to elaborate on a point or topic by providing additional details. Usually followed by the preposition 'on'.

    Example

    Could you expand on that point? I didn't quite understand the last part.

    Example

    In the second chapter, the author expands on the socio-economic factors that led to the revolution.

    Usage

    Usually takes the preposition 'on' when used intransitively.
  2. 4 to show subentries (v.)
    B1 Intermediate Technical Computing

    to click on a folder or list to see the items hidden inside it.

    to reveal the subentries of a hierarchical list, such as a directory tree or a menu.

    Example

    Click the plus sign to expand the folder and see all your files.

    Example

    The user interface allows you to expand each category to view the specific metadata associated with the individual records.
  3. 5 math expressions (v.)
    C1 Advanced Technical Math

    to rewrite a short math problem as a longer sum of parts.

    to rewrite an algebraic expression as a sum of terms without parentheses.

    Example

    The teacher asked the students to expand the equation on the board.

    Example

    When you expand the binomial expression, you can more easily identify the coefficients for each term.
Origin

Recorded in Middle English since 1422 (as expanden, expaunden), from Anglo-Norman espaundre, from Latin expandere (“to spread out”), itself from ex- (“out, outwards”) + pandō (“to spread”). Doublet of spawn.

Word family

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