Dance round the piano, then drive off (5)
I believe the answer is:
repel
'drive off' is the definition.
('repel' can be a synonym of 'drive off')
'dance round the piano' is the wordplay.
'dance' becomes 'reel' (reel is a kind of dance).
'round' indicates putting letters inside.
'the piano' becomes 'p'.
'reel' going around 'p' is 'REPEL'.
'then' acts as a link.
(Other definitions for repel that I've seen before include "Successfully resist" , "Be effective in controlling" , "Drive back or ward off" , "Put off - disgust" , "'Drive back, repulse (5)'" .)