A pan put back on (4)
I believe the answer is:
atop
'on' is the definition.
Both the definition and answer are adverbs. Maybe there's a link between them I don't understand?
'a pan put back' is the wordplay.
'pan' becomes 'pot' (both can mean a cooking vessel).
'put back' says the letters should be written backwards.
'pot' written backwards gives 'top'.
'a'+'top'='ATOP'
Can you help me to learn more?
(Other definitions for atop that I've seen before include "In superior position" , "Situated on" , "Surmounting" , "On the highest point" , "highest level" .)