Formerly named (3)
I believe the answer is:
'formerly named' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for nee that I've seen before include "Prefix indicating maiden name of married woman" , "Born (indicating a woman's maiden name)" , "Indicates the birth name of a married woman" , "Adjective denoting woman's name before marriage" , "Formerly named" .)