English Reference
noun

parameter

n.
US /pɝˈæmətɝ/ UK /pəɹˈæmɪtɐ/ pa·ram·e·ter UK spelling parameter's, parameter's

  1. 01 C1 Advanced Academic

    a limit or rule that controls how something should be done.

    a numerical or other measurable factor forming one of a set that defines a system or sets the conditions of its operation; often used in the plural to denote boundaries.

    Simple

    The researchers had to work within the strict parameters set by the government grant.

    In context

    The legal team spent weeks defining the parameters of the contract to ensure that every possible contingency was covered by the new regulations.

    Usage

    Commonly used in the plural form 'parameters' when referring to general guidelines or constraints.

    Pitfall
    We need to stay within the perimeters of the budget. We need to stay within the parameters of the budget.

    Learners often confuse 'parameter' (a rule or limit) with 'perimeter' (the outer edge of a physical area).

  2. 02 C1 Advanced Technical Computing

    a piece of information that you give to a computer program or function so it can do its work.

    a named variable in a function definition that acts as a placeholder for the argument passed to the function during execution.

    Simple

    This function requires two parameters: the user's name and their age.

    In context

    The developer modified the API to accept an optional parameter, allowing users to filter the search results by date or relevance.

    Usage

    In strict technical contexts, a 'parameter' is the variable defined in the function, while an 'argument' is the actual value passed to it.

  3. 03 C1 Advanced AcademicTechnical Science

    a fixed value that describes a specific part of a population or system.

    a quantity that is constant in a particular case but varies in others; specifically, a numerical characteristic of a population.

    Simple

    The study measured several parameters, including heart rate and blood pressure.

    In context

    In this statistical model, the population mean is the primary parameter we are attempting to estimate through random sampling.

Usage parameter space · define parameter · important parameter

As he explained, turning one knob can cause 50 others to react, so you have to find the sweet spot for each parameter to ensure everything works in harmony.

Ars Technica· 10 Jul 2026

Back at his desk, Truszynski came up with a list of parameters for his search.

Smithsonian Magazine· 27 Jul 2026

From French paramètre, from New Latin parametrum (“parameter”), from Ancient Greek παρα- (para-, “beside”) + μέτρον (métron, “measure”).

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

This entry
Origin Ancient Greek παρα-
Level C1 · Advanced
Frequency Frequent
Updated