Blokes gathered round island monument (7)
I believe the answer is:
obelisk
'monument' is the definition.
(type of monument or landmark)
'blokes gathered round island' is the wordplay.
'gathered' indicates anagramming the letters (the letters are gathered into a new order).
'round' means one lot of letters goes inside another.
'island' becomes 'i' (geographical abbreviation).
'blokes' is an anagram of 'obelsk'.
'obelsk' placed around 'i' is 'OBELISK'.
(Other definitions for obelisk that I've seen before include "Stone pillar tapering towards a point" , "Ancient Egyptian monument" , "Tapering monumental pillar" , "Tapering pillar erected as monument" , "Stone "needle"" .)