Woman changing gender in France in short trousers (4)
I believe the answer is:
jean
'woman changing gender in france' is the definition.
(Jean is a man's name in France)
'short trousers' is the wordplay.
'short' means to remove the last letter.
'trousers' becomes 'jeans' (denim trousers).
'jeans' with its final letter taken off is 'JEAN'.
'in' acts as a link.
(Other definitions for jean that I've seen before include "Girl's name" , "Heavy cloth, denim" , "Woman" , "Material" , "Frenchman" .)