Mum in bother with desire for playwright (10)
I believe the answer is:
dramaturge
'playwright' is the definition.
(thesaurus)
'mum in bother with desire' is the wordplay.
'mum' becomes 'ma' ('ma' can be a synonym of 'mum').
'in' is an insertion indicator.
'bother' becomes 'drat' (exclamation of annoyance).
'with desire' becomes 'urge' (I've seen this before. I am not sure about the 'with' bit.**).
'ma' inserted into 'drat' is 'dramat'.
'dramat'+'urge'='DRAMATURGE'
'for' is the link.
(Other definitions for dramaturge that I've seen before include "playwright" , "one's ended up in theatre" , "specialist in theatre" .)