Unable to be changed without exception. / (programming, of a variable) Not able to be altered in the memory after its value is set initially.

Something that cannot be changed.

plural of immutable

The state of being immutable; unchangeableness.

plural of immutability

plural of immutation

change; alteration; mutation

present participle of immute

simple past tense and past participle of immute

(obsolete, transitive) To change or alter.