Take away inferior piece of land? (8)
I believe the answer is:
subtract
'take away' is the definition.
(thesaurus)
'inferior piece of land?' is the wordplay.
'inferior' becomes 'sub'.
'piece of land?' becomes 'tract' ('tract' can be a synonym of 'piece of land'**).
'sub'+'tract'='SUBTRACT'
(Other definitions for subtract that I've seen before include "Withdraw" , "Take an amount away" , "Knock off" , "Deduct" , "dock" .)