English Reference
noun

idiom

n.
US /ˈɪdiəm/ UK /ˈɪdɪəm/ id·iom UK spelling idioms

  1. 01 B1 Intermediate

    a group of words that has a special meaning which you cannot guess by looking at the words alone.

    a fixed phrase whose figurative meaning is not deducible from the literal definitions of its constituent parts.

    Simple

    To 'kick the bucket' is a common English idiom that means to die.

    In context

    Learners often struggle with idioms because the literal translation of the words rarely provides a clue to the actual intended meaning.

    Pitfall
    I don't understand the idiom of 'break a leg'. I don't understand the idiom 'break a leg'.

    When naming a specific idiom, do not use 'of' between the word idiom and the phrase itself.

    expressionphrasefigure of speech
  2. 02 C1 Advanced AcademicFormal

    the particular way that a group of people or a language expresses ideas.

    the characteristic mode of expression or linguistic style peculiar to a specific language, region, or group.

    Simple

    The poet wrote in the local idiom of the mountain villages.

    In context

    The author successfully captured the legal idiom of the nineteenth century, making the courtroom scenes feel authentic to the period.

  3. 03 C1 Advanced Academic Music

    a style or way of doing something in art, music, or architecture.

    a distinct style or character of expression within a specific artistic, musical, or architectural movement.

    Simple

    The composer moved away from classical music and began writing in a jazz idiom.

    In context

    While the building uses modern materials, its design remains firmly rooted in the neoclassical idiom of the surrounding district.

  4. 04 C1 Advanced Technical Computing

    the natural or standard way to write code in a specific programming language.

    a standard way of performing a common task in a specific programming language that is considered natural by experienced developers.

    Simple

    Using a list comprehension is the preferred idiom for this task in Python.

    In context

    The developer refactored the legacy code to better follow modern C++ idioms, significantly improving both readability and performance.

    Usage

    Often used in the adjective form 'idiomatic' to describe clean, standard code.

She memorises idioms and appreciates the looser Chinese grammar, compared with Latin and Romance languages.

The Guardian· 10 Sept 2026

From Middle French idiome, and its source, Late Latin idioma, from Ancient Greek ἰδίωμα (idíōma, “a peculiarity, property, a peculiar phraseology, idiom”), from ἰδιοῦσθαι (idioûsthai, “to make one's own, appropriate to oneself”), from ἴδιος (ídios, “one's own, pertaining to oneself, private, personal, peculiar, separate”). By surface analysis, idi- + -om.

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

This entry
Origin Ancient Greek ἰδίωμα
Level C1 · Advanced
Frequency Occasional
Updated