Half of Polperro is north of river? That’s not right (5)
I believe the answer is:
error
'not right' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'half of polperro is north of river?' is the wordplay.
'half of' indicates taking half.
'is north of' says to put letters next to each other (in a down clue, some letters go above others).
'river?' becomes 'r' (abbreviation for river).
'polperro' with half the letters taken is 'erro'.
'erro'+'r'='ERROR'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for error that I've seen before include "Blunder, slip" , "Faulty judgment" , "Slip, mistake" , "Faux pas" , "Mistake, lapse" .)