Great singer takes most of bed (4)
I believe the answer is:
diva
'great singer' is the definition.
(I've seen this before)
'most of bed' is the wordplay.
'most of' means to remove the last letter.
'bed' becomes 'divan' (I've seen this before).
'divan' with its last letter removed is 'DIVA'.
'takes' is the link.
(Other definitions for diva that I've seen before include "Prima dona" , "Avid like opera singer" , "Celebrated female operatic star" , "One who sings" , "High-maintenance opera singer?" .)