Briefly bed leading lady (4)
I believe the answer is:
diva
'leading lady' is the definition.
(thesaurus)
'briefly bed' is the wordplay.
'briefly' means to remove the last letter.
'bed' becomes 'divan' (I've seen this before).
'divan' with its last letter removed is 'DIVA'.
(Other definitions for diva that I've seen before include "High-maintenace woman" , "A female opera singer" , "Great singer" , "demanding woman" , "fat lady?" .)