Mother dawdles and wastes the doctor's time (9)
I believe the answer is:
malingers
'wastes the doctor's time' is the definition.
Although both the answer and definition are verbs in their -s form, I can't see how they can define each other.
'mother dawdles' is the wordplay.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'dawdles' becomes 'lingers' ('linger' can be a synonym of 'dawdle').
'ma'+'lingers'='MALINGERS'
'and' acts as a link.
Can you help me to learn more?
(Another definition for malingers that I've seen is " avoids duty".)