Notes area of boggy ground (4)
I believe the answer is:
mire
'boggy ground' is the definition.
(I've seen this before)
'notes area of' is the wordplay.
'notes' becomes 'mi'.
'area of' becomes 're' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'mi'+'re'='MIRE'
Can you help me to learn more?
(Other definitions for mire that I've seen before include "Cause to get stuck (in soft mud?)" , "Soft mud or dirt" , "Emir found in mud" , "Morass" , "Swampy ground" .)