Being impulsive, write a hundred credit notes on an Italian island (10)
I believe the answer is:
capricious
'being impulsive' is the definition.
(synonyms)
'hundred credit notes on an italian island' is the wordplay.
'hundred' becomes 'c' (Roman numeral).
'credit notes' becomes 'ious' (I can't justify this - if you can you should give a lot more credence to this answer).
'on' means one lot of letters go next to another.
'an italian island' becomes 'capri' (I've seen this in another clue).
'c'+'ious'='cious'
'cious' put after 'capri' is 'CAPRICIOUS'.
'write a' is the link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for capricious that I've seen before include "Arbitrary and inconsistent" , "on a whim" , "Given to sudden mood swings" , "Changeable in mood" .)