Get rid of old lady’s area of expertise (6)
I believe the answer is:
domain
'area of expertise' is the definition.
'domain' can be an answer for 'area' (synonyms). I'm not sure about the 'of expertise' bit.
'get rid of old lady's' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'old lady' could be 'ma' (both can mean mother) and 'ma' is found within the answer.
The remaining letters 'din' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for domain that I've seen before include "Realm or range of influence" , "Sphere of activity" , "Sphere or territory" , "Range of influence or field of thought" , "Scope of knowledge - owned land" .)