Set-up of popular stop with everyone inside (12)
I believe the answer is:
installation
'set-up' is the definition.
Both the answer and definition are singular nouns.
Perhaps there's an association between them I don't understand?
'popular stop with everyone inside' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'stop with' becomes 'station' (eg a stop on a train journey. I am not sure about the 'with' bit.).
'everyone' becomes 'all' (all people).
'inside' is an insertion indicator.
'station' enclosing 'all' is 'stallation'.
'in'+'stallation'='INSTALLATION'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for installation that I've seen before include "Apparatus positioned" , "Large gallery artwork" , "Art exhibit in gallery" , "Exhibit constructed in a gallery" , "Positioning" .)