constancy

American  

[kon-stuhn-see] / ˈkɒn stən si /

noun

1. the quality of being unchanging or unwavering, as in purpose, love, or loyalty; firmness of mind; faithfulness.

   Synonyms:

   devotion, loyalty, fealty, fidelity, resolution

   Antonyms:

   infidelity, irresolution

2. uniformity or regularity, as in qualities or conditions; invariableness.

   Synonyms:

   dependability, permanence

   Antonyms:

   variability

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constancy British  

/ ˈkɒnstənsɪ /

noun

1. the quality of having a resolute mind, purpose, or affection; steadfastness

2. freedom from change or variation; stability

3. psychol the perceptual phenomenon in which attributes of an object appear to remain the same in a variety of different presentations, e.g., a given object looks roughly the same size regardless of its distance from the observer

4. ecology the frequency of occurrence of a particular species in sample plots from a plant community

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Etymology

Origin of constancy

From the Latin word constantia, dating back to 1520–30; see constant, -ancy

Explanation

Something or someone that never changes, that stays the course, and that is more like a rock than a leaf blowing in the wind shows constancy. Have you ever noticed how some people change their minds every day? Someone like that isn't showing constancy. In parts of the world where the weather changes frequently, the weather has no constancy, whereas in San Francisco, where it's about 70 and mild for ten months of the year, the weather has constancy. If you take constancy — a good thing — too far, you have stubbornness — an undesirable quality.

Example Sentences

But its biggest power lies in its constancy.

From BBC • Jun. 23, 2025

But in fostering constancy for others, Bridget finds herself stuck in her grief.

From Salon • Feb. 13, 2025

“Younger children in particular, they rely on constancy in their lives to feel like everything’s OK,” said clinical psychologist Karen Rogers, of the National Center for School Crisis and Bereavement at Children’s Hospital L.A.

From Los Angeles Times • Jan. 18, 2025

This time around, there was no particularly huge boost at any given time but a constancy to the increased interest in “authentic.”

From Seattle Times • Nov. 26, 2023

What maintained its constancy or fidelity: What kept elephants from morphing into pigs, or kangaroos into beavers?

From "The Gene" by Siddhartha Mukherjee

Related Words

• dependability
• perseverance
• steadfastness
• steadiness
• trustworthiness
• truthfulness