Shunning a cove and swimming around island (9)
I believe the answer is:
avoidance
'shunning' is the definition.
('avoidance' can be a synonym of 'shunning')
'a cove and swimming around island' is the wordplay.
'swimming' indicates anagramming the letters.
'around' indicates putting letters inside.
'island' becomes 'i'.
'a'+'cove'+'and'='acoveand'
'acoveand' is an anagram of 'avodance'.
'avodance' enclosing 'i' is 'AVOIDANCE'.
(Other definitions for avoidance that I've seen before include "Not dealing with" , "ducking" , "Steering clear of" , "The shunning of something undesirable, like tax" , "Evasion" .)