Little Diana, modest but very attractive (5)
I believe the answer is:
dishy
'very attractive' is the definition.
(I've seen this before)
'little diana modest' is the wordplay.
'little diana' becomes 'di' (Di is short for Diana. I am not sure about the 'little' bit.).
'modest' becomes 'shy'.
'di'+'shy'='DISHY'
'but' acts as a link.
Can you help me to learn more?
(Other definitions for dishy that I've seen before include "Gorgeous" , "Good-looking (informal)" , "Good-looking (colloq.)" , "Fair" , "Attractive" .)