Capable of or subject to change or alteration. The mutable nature of fashion trends makes it difficult to keep up with the latest styles.
(Biology, Genetics) Liable or able to undergo mutation. Certain viruses have highly mutable genomes, allowing them to evade immune responses.
(Computing) Able to be modified after creation; not fixed or immutable. In many programming languages, strings are mutable objects that can be altered in place.
(Astrology) Relating to or designating the zodiacal modality that is adaptable and changeable (Gemini, Virgo, Sagittarius, Pisces). Mutable signs are believed to be flexible and quick to adjust to new circumstances.