Father Reed's mistaken, it's the other way round (8)
I believe the answer is:
reversed
'the other way round' is the definition.
Both the answer and definition are adjectives. Perhaps there's a link between them I don't understand?
'father reed's mistaken' is the wordplay.
'father' becomes 'rev' (I've seen this in other clues).
'mistaken' indicates anagramming the letters.
'reeds' anagrammed gives 'ersed'.
'rev'+'ersed'='REVERSED'
'it's' acts as a link.
Can you help me to learn more?
(Other definitions for reversed that I've seen before include "Moved backwards" , "Drove car backwards" , "Turned round" , "Put back to front" , "what the answer to the final clue [Send up and down (5)] might be" .)