National lad free to change (7)
I believe the answer is:
federal
'national' is the definition.
(similar in meaning)
'lad free to change' is the wordplay.
'to change' is an anagram indicator.
'lad'+'free'='ladfree'
'ladfree' with letters rearranged gives 'FEDERAL'.
(Other definitions for federal that I've seen before include "In alliance" , "Of the state" , "Relating to central government in the US" , "(Of a union or government) involving states voluntarily joined together for common purposes" , "Red flea (anag.)" .)