Clever dictionary includes ruling (7)
I believe the answer is:
verdict
'ruling' is the definition.
(thesaurus)
'clever dictionary includes' is the wordplay.
'includes' indicates the answer is hidden within the clue.
'VERDICT' is hidden within 'clever dictionary'.
(Other definitions for verdict that I've seen before include "where this is delivered" , "Could be innocent or guilty" , "The findings of a jury" , "Decision of a jury" , "Result of deliberation" .)