Italian girl showing cleavage in East (10)
I believe the answer is:
florentine
'italian' is the definition.
(I know that Florentine is a type of italian)
'girl showing cleavage in east' is the wordplay.
'girl showing' becomes 'flo' (I can't justify this - if you can you should give a lot more credence to this answer).
'cleavage' becomes 'rent' (both can mean a tear or split in something).
'east' becomes 'e' (abbreviation).
'flo'+'rent'+'in'+'e'='FLORENTINE'
Can you help me to learn more?
(Other definitions for florentine that I've seen before include "One kind of Italian" , "Biscuit with nuts and fruit" .)