Area almost separated from nearest breeding-ground (4)
I believe the answer is:
nest
'breeding-ground' is the definition.
(I've seen this before)
'area almost separated from nearest' is the wordplay.
'area' becomes 'n' (I can't explain this - if you can you should give a lot more credence to this answer).
'almost' becomes 'near' (near can mean almost or virtually).
'separated from' indicates named letters should be taken away.
'nearest' with 'near' removed is 'est'.
'n'+'est'='NEST'
Can you help me to learn more?
(Other definitions for nest that I've seen before include "Stack of tables" , "breeding-ground" , "Cosy retreat" , "Structure for laying eggs" , "Den" .)