One used when entering Florida island apartment?
I believe the answer is:
keypad
'one used when entering florida' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.
'island apartment?' is the wordplay.
'island' becomes 'key' (I've seen this before).
'apartment?' becomes 'pad' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'key'+'pad'='KEYPAD'
Can you help me to learn more?
(Other definitions for keypad that I've seen before include "What might help you calculate" , "where one may have pressing needs" , "In control, buttoned up" , "Perhaps remote" , "Feature used to operate a portable electronic device" .)