Somehow entrap guardian (6)
I believe the answer is:
parent
'guardian' is the definition.
(thesaurus)
'somehow entrap' is the wordplay.
'somehow' indicates anagramming the letters.
'entrap' anagrammed gives 'PARENT'.
(Other definitions for parent that I've seen before include "Author" , "The company of which others are subsidiaries" , "Raise" , "person responsible for children" , "One with children" .)