Support for women with essentially fine intellect (5)
I believe the answer is:
brain
'intellect' is the definition.
(I know that brain is a type of intellect)
'support for women with essentially fine' is the wordplay.
'support for women' becomes 'bra' (I've seen this in another clue).
'with' is a charade indicator (letters next to each other).
'essentially' means to look at the middle letters.
The middle letters of 'fine' are 'in'.
'bra'+'in'='BRAIN'
(Other definitions for brain that I've seen before include "Clever type" , "It's in the skull" , "and 15 ac. The loss of experts through emigration" , "Seat of the intellect" , "Hit hard; intellect" .)