Men can support shopping centre for holiday island (9)
I believe the answer is:
mallorcan
'for holiday island' is the definition.
(relating to or from Mallorca)
'men can support shopping centre' is the wordplay.
'men' becomes 'or' (military abbreviation for Other Ranks).
'support' means one lot of letters go next to another (in a down clue, some letters hold others up).
'shopping centre' becomes 'mall' (a mall is a large shopping complex).
'or'+'can'='orcan'
'orcan' after 'mall' is 'MALLORCAN'.
(Other definitions for mallorcan that I've seen before include "from Palma, perhaps" , "Islander" .)