Dianne when drunk is a different woman (6)
I believe the answer is:
nadine
'different woman' is the definition.
'Nadine' can be an answer for 'woman'. I am unsure of the 'different' bit.
'dianne when drunk' is the wordplay.
'when drunk' indicates anagramming the letters (a drunken or disorderly form of the letters).
'dianne' anagrammed gives 'NADINE'.
'is a' is the link.
Can you help me to learn more?
(Other definitions for nadine that I've seen before include "South African writer" , "French girl" , "Woman" , "Girl's name; Dianne (anag.)" .)