Prima donna needs first sofa (5)
I believe the answer is:
divan
'sofa' is the definition.
(I know that divan is a type of sofa)
'prima donna needs first' is the wordplay.
'prima donna' becomes 'diva' (synonyms).
'needs first' becomes 'n' (dst letter of 'needs').
'diva'+'n'='DIVAN'
(Other definitions for divan that I've seen before include "Sideless, backless couch" , "Piece of furniture" , "Sort of bed" , "Long backless sofa" , "Couch - bed" .)