A country area to spoil, on the quiet! (5)
I believe the answer is:
marsh
'a country area' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'spoil on the quiet' is the wordplay.
'spoil' becomes 'mar' (synonyms).
'on' is a charade indicator (letters next to each other).
'the quiet' becomes 'sh'.
'mar'+'sh'='MARSH'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for marsh that I've seen before include "Swampland" , "Waterlogged land" , "Quagmire" , "Wetland" , "Swampy ground" .)