Doctor to repeat work in theatre (8)
I believe the answer is:
operetta
'work in theatre' is the definition.
'operetta' can be an answer for 'work' (operetta is a type of musical work). I'm not certain of the 'in theatre' bit.
'doctor to repeat' is the wordplay.
'doctor' indicates an anagram.
'to'+'repeat'='torepeat'
'torepeat' anagrammed gives 'OPERETTA'.
Can you help me to learn more?
(Other definitions for operetta that I've seen before include "Light musical drama" , "Light classical music comedy-drama" , "light-hearted performance" , "some music theatre" , "Light entertainment" .)