Accustomed to nut and date assortment (7)
I believe the answer is:
attuned
'accustomed' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Maybe you can see a link between them that I can't see?
'nut and date assortment' is the wordplay.
'and' says to put letters next to each other.
'assortment' indicates anagramming the letters.
'nut' put after 'date' is 'datenut'.
'datenut' with letters rearranged gives 'ATTUNED'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for attuned that I've seen before include "On the same wavelength" , "Receptive" .)