Even a sequel shot around island (8)
I believe the answer is:
equalise
'even' is the definition.
(I've seen this before)
'a sequel shot around island' is the wordplay.
'shot' indicates an anagram.
'around' is an insertion indicator.
'island' becomes 'i'.
'a'+'sequel'='asequel'
'asequel' with letters rearranged gives 'equalse'.
'equalse' enclosing 'i' is 'EQUALISE'.
(Other definitions for equalise that I've seen before include "Make evenly balanced, scores say" , "Level a match score" , "Get even" , "Become the same level" , "Get, make level" .)