Pop round to see a wall panel (4)
I believe the answer is:
dado
'a wall panel' is the definition.
(I've seen this before)
'pop round to' is the wordplay.
'pop' becomes 'dad' ('dad' can be a synonym of 'pop').
'round' means to look at the middle letters.
'to' becomes 'for'.
The middle of 'for' is 'o'.
'dad'+'o'='DADO'
'see' acts as a link.
(Other definitions for dado that I've seen before include "Decorated lower part of an interior wall" , "Panelled lower part of a wall" , "Lower section of wall in room" , "strip running round room" , "part of wall specially decorated" .)