Changeless Malibu met changes (9)
I believe the answer is:
immutable
'changeless' is the definition.
(I know that changeless can be written as immutable)
'malibu met changes' is the wordplay.
'changes' indicates anagramming the letters.
'malibu'+'met'='malibumet'
'malibumet' with letters rearranged gives 'IMMUTABLE'.
(Other definitions for immutable that I've seen before include "Not able to be changed" , "Changeless" .)