Left in Cuba without a weapon (4)
I believe the answer is:
club
'weapon' is the definition.
(I've seen this before)
'left in cuba without a' is the wordplay.
'left' becomes 'l' (common abbreviation**).
'in' indicates putting letters inside.
'without' is a deletion indicator.
'cuba' with 'a' removed is 'cub'.
'l' inserted inside 'cub' is 'CLUB'.
(Other definitions for club that I've seen before include "wood, perhaps" , "may give members benefits" , "Iron or putter, say" , "Batter" , "'Short stick, card suit and association (4)'" .)