What does mutable mean?
Mutable means capable of being changed, altered, or modified. The word is especially useful when discussing ideas, conditions, systems, or data that are not permanently fixed. For example, a plan may be mutable if it can still be revised, while an object in software may be mutable if its contents or properties can be changed after its creation. Its connotations are generally neutral, although it can sometimes suggest that something is provisional or open to revision. Mutable is more formal and technical than everyday alternatives such as changeable or alterable, and it is commonly associated with the distinction between mutable and immutable things. The word comes from the Latin mutabilis, meaning changeable, and belongs to the same root as mutation, mutant, and immute. Understanding mutable emphasizes that a thing's present state is not necessarily its final or permanent state.
adjectiveCapable of being changed, altered, or modified; changeable.
- Capable of being changed, altered, or modified.
"The researcher recorded each mutable factor so that later changes could be tracked."
"The agreement remained mutable until the final signatures were collected."
"In programming, a mutable list can be changed after it has been created."
Mutable describes anything that refuses to be fixed forever: a plan, a variable, or even a future.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does mutable come from?
Mutable was borrowed into English from Latin mutabilis, meaning “changeable,” which was formed from mutare, “to change.” The same Latin root also produced words such as mutate, mutation, mutant, and immute. In English, mutable developed into a formal adjective for things that can be altered or revised.
Related word forms
How mutable is actually used
Usually formal or technical. It describes the possibility of change, not necessarily instability or frequent change; in computing, it contrasts with immutable.