Land conspiracy (4)
I believe the answer is:
plot
I believe this clue is a double definition.
'land' is the first definition.
(thesaurus)
'conspiracy' is the second definition.
(I've seen this before)
(Other definitions for plot that I've seen before include "Concoct schemes" , "Make map" , "Ground - plan" , "part of garden" , "Graph; piece of ground" .)