Drama is rank at the start (7,5)
I believe the answer is:
private lives
'drama' is the definition.
(play by Noel Coward)
'is rank at the start' is the wordplay.
'is' becomes 'lives'.
'rank' becomes 'private' (I've seen this before).
'at the start' means one lot of letters go next to another.
'lives' after 'private' is 'PRIVATE LIVES'.
(Other definitions for private lives that I've seen before include "Noel Coward comedy" , "Play by Noel Coward" , "stage entertainment" .)