See more synonyms for rigorous on Thesaurus.com
  1. characterized by rigor; rigidly severe or harsh, as people, rules, or discipline: rigorous laws.
  2. severely exact or accurate; precise: rigorous research.
  3. (of weather or climate) uncomfortably severe or harsh; extremely inclement.
  4. Logic, Mathematics. logically valid.

Origin of rigorous

First recorded in 1350–1400; Middle English word from Medieval Latin word rigōrōsus. See rigor, -ous
Related formsrig·or·ous·ly, adverbrig·or·ous·ness, nouno·ver·rig·or·ous, adjectiveo·ver·rig·or·ous·ly, adverbo·ver·rig·or·ous·ness, nounself-rig·or·ous, adjectivesem·i·rig·or·ous, adjectivesem·i·rig·or·ous·ly, adverbsem·i·rig·or·ous·ness, nounun·rig·or·ous, adjectiveun·rig·or·ous·ly, adverbun·rig·or·ous·ness, noun

Synonyms for rigorous

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1. stern, austere, hard, inflexible, stiff, unyielding. See strict. 2. demanding, finical. 3. hard, bitter.

Antonyms for rigorous

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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Contemporary Examples of rigorous

Historical Examples of rigorous

British Dictionary definitions for rigorous


  1. characterized by or proceeding from rigour; harsh, strict, or severerigorous discipline
  2. severely accurate; scrupulousrigorous book-keeping
  3. (esp of weather) extreme or harsh
  4. maths logic (of a proof) making the validity of the successive steps completely explicit
Derived Formsrigorously, adverbrigorousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for rigorous

late 14c., from Old French rigorous (13c., Modern French rigoureux), from Medieval Latin rigorosus, from Latin rigor (see rigor). Related: Rigorously.

Online Etymology Dictionary, © 2010 Douglas Harper