A boundary to open farmland belonging to us (4)
I believe the answer is:
four
'a boundary' is the definition.
(type of score in cricket)
'open farmland belonging to us' is the wordplay.
'open farmland' becomes 'f' (I can't justify this - if you can you should believe this answer much more).
'belonging to us' becomes 'our' (I've seen this before).
'f'+'our'='FOUR'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for four that I've seen before include "Number of Eliot Quartets" , "Square root of sixteen" , "teatime?" , "Figure" , "10 cleared of misuse of fortune" .)