Programme that's mature and different (6)
I believe the answer is:
agenda
'programme' is the definition.
(I know that agenda is a type of programme)
'mature and different' is the wordplay.
'mature' becomes 'age' (synonyms).
'different' is an anagram indicator (letters placed in a different order).
'and' anagrammed gives 'nda'.
'age'+'nda'='AGENDA'
'that's' acts as a link.
(Other definitions for agenda that I've seen before include "List of items to be done" , "List of items to be dealt with" , "Matters to be addressed" , "List of items for committee to consider" , "Business to be transacted" .)