Where it could be nice for mum to just sit and watch (6)
I believe the answer is:
cinema
'where it could' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'nice for mum to just sit and watch' is the wordplay.
I cannot quite see how this works, but
an anagram of 'nice' is 'cine' which is located in the answer.
'mum' could be 'ma' (ma can mean mother) and 'ma' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'be' acts as a link.
Can you help me to learn more?
(Other definitions for cinema that I've seen before include "Iceman (anag)" , "Place of entertainment" , "Silver screen" , "Movie-house" , "(Building showing) films" .)