Big picture: someone childless is neither a ____ (8)
I believe the answer is:
panorama
'big picture' is the definition.
'panorama' can be an answer for 'picture' (I've seen this before). I'm not sure about the 'big' bit.
'someone childless is neither a' is the wordplay.
I cannot really see how this works, but
'neither' could be 'nor' (I've seen this before) and 'nor' is found in the answer.
'a' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for panorama that I've seen before include "Distant view of a wide area" , "Am on a par (anag)" , "Wide vista" , "Extensive all-round view" , "Picture" .)