IPA: /ɪˌmjuːtəˈbɪləti/
KK: /ɪˌmjuːtəˈbɪləti/
The quality of being unchangeable or unable to be altered.
The immutability of the laws of physics means they do not change over time.
Immutability is formed from "in-" (meaning not) and "mutabilis" (from Latin "mutare", meaning to change) and the suffix "-ity" (meaning the state or quality of). The word describes the state of being not able to change or unchangeable.
Think of 'not changing' ('in-' means not and 'mutabilis' relates to change) to remember that 'immutability' refers to the quality of being unchangeable.