Trains in playing fields (7)
I believe the answer is:
grounds
This might be a double definition.
'trains' is the first definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps there's an association between them I don't understand?
'playing fields' is the second definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Perhaps there's a link between them I don't understand?
'in' acts as a link.
Can you help me to learn more?
(Other definitions for grounds that I've seen before include "Coffee sediment" , "Basis for belief" , "justification" , "Refuses authority to fly" , "Reasons" .)