Dissolute shark I agitated (6)
I believe the answer is:
rakish
'dissolute' is the definition.
(thesaurus)
'shark i agitated' is the wordplay.
'agitated' is an anagram indicator.
'shark'+'i'='sharki'
'sharki' is an anagram of 'RAKISH'.
(Other definitions for rakish that I've seen before include "Jaunty; dissolute" , "Jaunty; fast-looking (boat)" , "Given to philandering" , "Jaunty and irresponsible" , "abandoned" .)