Holiday island where military officer gets about (7)
I believe the answer is:
majorca
'holiday island' is the definition.
(I've seen this before)
'military officer gets about' is the wordplay.
'military officer' becomes 'major' (major is a kind of military officer).
'gets' says to put letters next to each other.
'about' becomes 'ca' (abbreviation for circa).
'major'+'ca'='MAJORCA'
'where' acts as a link.
(Other definitions for majorca that I've seen before include "Palma its capital" , "Holiday island" , "Main Balearic island" , "holiday destination ..." , "Largest of the Balearic Islands" .)