Insipid diva staggering round the piano (5)
I believe the answer is:
vapid
'insipid' is the definition.
(I know that insipid can be written as vapid)
'diva staggering round the piano' is the wordplay.
'staggering' indicates an anagram (letters stagger around).
'round' is an insertion indicator.
'the piano' becomes 'p' (musical abbreviation).
'diva' with letters rearranged gives 'vaid'.
'vaid' placed around 'p' is 'VAPID'.
(Other definitions for vapid that I've seen before include "Insipid - lacking significance" , "Boring or lifeless" , "Insipid or uninteresting" , "Insipid, empty" , "Boring, flat" .)