English Reference
noun

rigor

n.
US /ˈɹɪɡɝ/ UK /ɹˈɪɡɐ/ rig·or UK spelling rigors, rigour

  1. 01 B2 Upper Intermediate American English

    the quality of being very careful, thorough, and exact.

    the quality of being extremely thorough, exhaustive, or accurate. Often used in academic or professional contexts to describe high standards.

    Simple

    The university is known for the academic rigor of its science programs.

    In context

    The study was criticized for lacking the statistical rigor necessary to support such a controversial conclusion.

    Usage

    Uncountable in this sense.

    Teacher's tip

    Remind students that this is the American spelling; British English uses 'rigour'.

    strictnessthoroughnessprecision
    laxitycarelessness
  2. 02 C1 Advanced American EnglishFormal

    the difficult or unpleasant conditions of something.

    the harsh, demanding, or unpleasant conditions of a particular environment or lifestyle.

    Simple

    The soldiers were trained to survive the rigors of the desert.

    In context

    Few explorers were prepared for the physical rigors of the expedition across the frozen tundra.

    Usage

    Usually used in the plural form: 'the rigors of'.

  3. 03 C2 Proficiency Technical Medicine

    a sudden feeling of cold with shivering and a high temperature.

    a sudden attack of shivering and a feeling of coldness, typically accompanied by a rapid rise in body temperature.

    Simple

    The patient suffered a severe rigor shortly after the surgery.

    In context

    The onset of a high fever was preceded by a violent rigor that lasted for nearly twenty minutes.

    Usage

    Countable in medical reports.

At some point, a person becomes too famous to submit to the rigours of a weekly magazine show.

The Guardian· 28 Aug 2026

From Old French, from Latin rigor (“stiffness, rigidity, rigor, cold, harshness”), from rigere (“to be rigid”).

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

This entry
Origin Latin rigor
Level C1 · Advanced
Frequency Occasional
Updated