Pretence spread around island that's where the action is (9)
I believe the answer is:
epicentre
'where the action is' is the definition.
The answer is a location as well as being a singular noun. This is suggested by the definition.
'pretence spread around island' is the wordplay.
'spread' indicates anagramming the letters.
'around' means one lot of letters goes inside another.
'island' becomes 'i' (geographical abbreviation).
'pretence' anagrammed gives 'epcentre'.
'epcentre' placed around 'i' is 'EPICENTRE'.
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for epicentre that I've seen before include "in the middle" , "a very disturbed place" , "Earthquake's surface location" , "most shocking point" , "Shocking scene" .)