[ rig-er-uhs ]
/ ˈrɪg ər əs /


characterized by rigor; rigidly severe or harsh, as people, rules, or discipline: rigorous laws.
severely exact or accurate; precise: rigorous research.
(of weather or climate) uncomfortably severe or harsh; extremely inclement.
Logic, Mathematics. logically valid.

Origin of rigorous

First recorded in 1350–1400; Middle English word from Medieval Latin word rigōrōsus. See rigor, -ous


2 demanding, finical.
3 hard, bitter.

Related forms

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

Examples from the Web for rigorous

British Dictionary definitions for rigorous


/ (ˈrɪɡərəs) /


characterized by or proceeding from rigour; harsh, strict, or severerigorous discipline
severely accurate; scrupulousrigorous book-keeping
(esp of weather) extreme or harsh
maths logic (of a proof) making the validity of the successive steps completely explicit

Derived Forms

rigorously, 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