Around island, I cannot shake inertia (8)
I believe the answer is:
inaction
'inertia' is the definition.
(I've seen this before)
'around island i cannot shake' is the wordplay.
'around' indicates putting letters inside.
'island' becomes 'i' (geographical abbreviation).
'shake' indicates an anagram.
'i'+'cannot'='icannot'
'icannot' anagrammed gives 'inacton'.
'i' going into 'inacton' is 'INACTION'.
(Other definitions for inaction that I've seen before include "lack of engagement" , "Failure to exert oneself" , "Sloth" , "Stasis" , "Lethargy -- not in CIA (anag)" .)