Hard to understand this mother with jewellery (8)
I believe the answer is:
mumbling
'hard to understand this' is the definition.
The definition suggests a singular noun which matches the answer.
'mother with jewellery' is the wordplay.
'mother' becomes 'mum' (informal term for mother).
'with' says to put letters next to each other.
'jewellery' becomes 'bling' (informal term for jewellery).
'mum'+'bling'='MUMBLING'
Can you help me to learn more?
(Other definitions for mumbling that I've seen before include "Not clearly saying" , "Talking indistinctly" , "Muttering" .)