mutable

American  

[myoo-tuh-buhl] / ˈmyu tə bəl /

adjective

1. liable or subject to change or alteration.

   Synonyms:

   variable, changeable

2. given to changing; constantly changing; fickle or inconstant.

   the mutable ways of fortune.

   Synonyms:

   unsteady, unsettled, vacillating, unstable

   Antonyms:

   stable

3. Computers. (in object-oriented programming) of or noting an object having properties whose values can change while the object itself maintains a unique identity.

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mutable British  

/ ˈmjuːtəbəl /

adjective

1. able to or tending to change

2. astrology of or relating to four of the signs of the zodiac, Gemini, Virgo, Sagittarius, and Pisces, which are associated with the quality of adaptability Compare cardinal fixed

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Other Word Forms

• hypermutable adjective
• hypermutably adverb
• mutability noun
• mutableness noun
• mutably adverb
• nonmutable adjective
• nonmutably adverb
• unmutable adjective

Etymology

Origin of mutable

First recorded in 1350–1400; Middle English, from Latin mūtābilis, equivalent to mūtā(re) “to change” + -bilis -ble

Explanation

Something or someone that is mutable is subject to change. Mutable weather can go from sunny, to rainy and windy, and back to sunny again. The word mutable originally had a negative connotation, and it referred to a person, usually a poet, who frequently changed his mind and moods. Mutable has come to mean anything that is capable of changing form or quality. If your favorite restaurant offers seasonal food, the menu is probably mutable with the change in seasons. In science, the word mutable refers to an organism or a gene that, for better or worse, changes its form.

Example Sentences

“A Child’s Christmas in Wales” aptly reflects the way that holiday images randomly flare up and recede within the bright hearth of recollection, memories made mutable by the passage of time.

From The Wall Street Journal • Dec. 19, 2025

The staging is a practical arrangement, but it is also a presentation meant to convey gravitas and to ensure everyone can keep an eye on their mutable front man.

From Salon • May 13, 2025

Still, “It showed that those sites are mutable in these viruses,” says Tom Peacock, an influenza virologist at the Pirbright Institute.

From Science Magazine • Dec. 5, 2024

In the course of his restless, mutable career, Gordon, 72, has written all kinds of music, from classical pieces for solo piano or chamber orchestra to dance scores and experimental operas.

From New York Times • Apr. 23, 2024

Muller’s experiments demonstrated that heredity could be manipulated quite easily: the mutation rate was itself quite mutable.

From "The Gene" by Siddhartha Mukherjee