Permit lent it legitimacy in part (7)
I believe the answer is:
entitle
'permit' is the definition.
(thesaurus)
'lent it legitimacy in part' is the wordplay.
'in part' indicates a hidden word.
'ENTITLE' is hidden within 'lent it legitimacy'.
(Other definitions for entitle that I've seen before include "Warrant" , "confer rank" , "Call; permit" , "Give (someone) rights" , "Allow" .)