ENGLISH
REFERENCE

reliability

n.
US //ɹiˌɫaɪəˈbɪɫəti// UK //ɹɪlˌaɪəbˈɪlɪti// re·li·a·bil·i·ty
  1. 1 trustworthiness (n.)
    B2 Upper Intermediate

    the quality of being able to be trusted or relied on.

    the quality of being dependable, consistent, or trustworthy in character or performance.

    Example

    The company is famous for the reliability of its cars, which rarely break down.

    Example

    The manager questioned the reliability of the witness's testimony after several inconsistencies were discovered during the cross-examination.

    Usage

    Uncountable in general usage.
    • unreliability
    • fickleness
  2. 2 consistency of measurement (n.)
    C1 Advanced Academic Technical Science

    the ability of a test or tool to give the same result every time you use it.

    the degree to which an assessment tool produces stable and consistent results over repeated trials.

    Example

    The researchers checked the reliability of the survey by giving it to the same group twice.

    Example

    High reliability does not necessarily imply validity; a scale might consistently overstate weight by five kilograms, making it reliable but inaccurate.

    Usage

    Often contrasted with 'validity' in research contexts.
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  1. 3 technical performance (n.)
    C1 Advanced Technical Science

    how long a machine or system works before it fails or breaks.

    the probability that a system or component will perform its required function under stated conditions for a specified period.

    Example

    Engineers are working to improve the reliability of the new power grid.

    Example

    The aerospace industry demands extreme levels of reliability, as even a minor component failure can have catastrophic consequences during flight.

    Usage

    Commonly used in engineering and systems design.
Origin

From reliable + -ity.

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