Mutable: adjective

Cambridge Dictionary

"able or likely to change"

mutableCambridgeWords

Merriam-Webster

"capable of change or of being changed"

Definition of MUTABLEMerriamWebster

Mozilla

"Mutable is a type of variable that can be changed. In JavaScript, only objects and arrays are mutable, not primitive values."

Mutable - MDN Web Docs Glossary: Definitions of Web-related terms | MDN

Mutable vs Immutable

Mutable vs Immutable - What's the difference?WikiDiff