immutable

UK: /ɪˈmjuːtəb^əl/ US: /ɪˈmjutəbəl/ ,(i myo̅o̅′tə bəl)

WordReference Random House Learner's Dictionary of American English © 2025

im•mu•ta•ble /ɪˈmyutəbəl/   adj. 

1. unchangeable:
   the immutable laws of physics.

im•mu•ta•bil•i•ty /ɪˌmyutəˈbɪlɪti/  n. [uncountable]
im•mu•ta•bly, adv. See -mut-.

WordReference Random House Unabridged Dictionary of American English © 2025

im•mu•ta•ble  (i myo̅o̅′tə bəl), adj. 

1. not mutable;
   unchangeable;
   changeless.

• Latin immūtābilis. See im-², mutable
• late Middle English 1375–1425

im•mu′ta•bil′i•ty, im•mu′ta•ble•ness, n. 
im•mu′ta•bly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

immutable / ɪˈmjuːtəbəl/ adjective

1. unchanging through time; unalterable; ageless: immutable laws

imˌmutaˈbility, imˈmutableness noun