Main definitions of rigor in US English:

: rigor1rigor2

rigor1

noun

Medicine
  • 1A sudden feeling of cold with shivering accompanied by a rise in temperature, often with copious sweating, especially at the onset or height of a fever.

    1. 1.1
      short for rigor mortis

Origin

Late Middle English: from Latin, literally ‘stiffness’, from rigere ‘be stiff’.

Pronunciation

rigor

/ˈrɪɡər//ˈriɡər/

Main definitions of rigor in US English:

: rigor1rigor2

rigor2

(British rigour)

noun

  • 1The quality of being extremely thorough, exhaustive, or accurate.

    ‘his analysis is lacking in rigor’
    meticulousness, thoroughness, carefulness, attention to detail, diligence, scrupulousness, exactness, exactitude, precision, accuracy, correctness, strictness, punctiliousness, conscientiousness
    View synonyms
    1. 1.1 Severity or strictness.
      ‘the full rigor of the law’
      strictness, severity, sternness, stringency, austerity, toughness, hardness, harshness, rigidity, inflexibility
      View synonyms
    2. 1.2rigors Demanding, difficult, or extreme conditions.
      ‘the rigors of a harsh winter’
      hardship, harshness, severity, adversity, suffering, privation, ordeal, misery, distress, trial
      View synonyms

Origin

Late Middle English: from Old French rigour from Latin rigor ‘stiffness’.

Pronunciation

rigor

/ˈrɪɡər//ˈriɡər/