rigor

American  

[rig-er] / ˈrɪg ər /

especially British, rigour

noun

1. strictness, severity, or harshness, as in dealing with people.

   Synonyms:

   stringency, inflexibility

2. the full or extreme severity of laws, rules, etc.

3. severity of living conditions; hardship; austerity.

   the rigor of wartime existence.

4. a severe or harsh act, circumstance, etc.

   Synonyms:

   cruelty

5. scrupulous or inflexible accuracy or adherence.

   the logical rigor of mathematics.

6. severity of weather or climate or an instance of this.

   the rigors of winter.

7. Pathology. a sudden coldness, as that preceding certain fevers; chill.

8. Physiology. a state of rigidity in muscle tissues during which they are unable to respond to stimuli due to the coagulation of muscle protein.

9. Obsolete. stiffness or rigidity.

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rigor British  

/ ˈraɪɡɔː, ˈrɪɡə /

noun

1. med a sudden feeling of chilliness, often accompanied by shivering: it sometimes precedes a fever

2. pathol rigidity of a muscle; muscular cramp

3. a state of rigidity assumed by some animals in reaction to sudden shock

4. the inertia assumed by some plants in conditions unfavourable to growth

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Usage

What is rigor? Rigor is strictness and inflexibility, as in The military academy was known for its dedication to perfection, discipline, and rigor. Rigor is also hardship or austerity, as in Young soldiers are rarely ready to handle the rigors of war. Rigor can also refer to a strict accuracy, as with scientific experiments. If a teacher is known for their rigor, they are very strict about things like students finishing all their homework and are likely to punish students who don’t follow the rules. A person known for rigor is likely to support punishments for people who misbehave rather than rewards for people who behave. Rigor can also mean a condition that makes life harder, such as living without electricity. When referring to austerity, can mean living without a lot of things that make life pleasant, like takeout food, video games, and traveling. Finally, rigor can mean strict accuracy or precision, as in The report on water pollution was commended for its scientific rigor. In British English, this word is commonly spelled as rigour. The adjective form of rigor is rigorous and it is most often used to mean something is very harsh or full of difficulties, as in It takes years of rigorous training to be an Olympic athlete. Example: We nearly froze as we huddled in the log cabin and suffered through the rigors of the harsh, unforgiving winter.

Etymology

Origin of rigor

1350–1400; Middle English rigour < Latin rigor stiffness, equivalent to rig ( ēre ) to be stiff + -or -or ¹

Explanation

When a school boasts of its academic rigor, it means its students learn a lot and work really hard. Rigor means thoroughness and exhaustiveness — the gold standard for a good teacher. You may have heard of "rigor mortis" — which is a medical term describing the stiffness of a body after death. Another meaning of rigor is "sternness or severity" — for many, the rigors of boot camp are not easy to endure.

Example Sentences

This shift has sparked some controversy: Doctors’ groups say there is danger in deploying people who don’t undergo the rigor of medical school and residency to do unsupervised doctor-level work.

From The Wall Street Journal • May 16, 2026

So it took a real rigor for me to know that if I wasn’t where I needed to be, I had to get better.

From Los Angeles Times • May 7, 2026

“After several years of increased innovation and tighter financial rigor, efforts are manifesting in a materially healthier financial profile and growth trajectory,” Altmann wrote in a note Friday.

From Barron's • May 1, 2026

AP courses are designed to have the same rigor as a college class and are usually accepted for credit or placement when high-school students get to college.

From MarketWatch • Apr. 21, 2026

As much as I found Robbie to be snippy and inflexible, I’d also internalized her devotion to rigor.

From "Becoming" by Michelle Obama

Related Words

• accuracy
• austerity
• difficulty
• firmness
• hardship
• harshness
• ordeal
• precision
• rigidity
• tenacity
• tribulation
• vicissitude