Pure form of land (4)
I believe the answer is:
peru
'land' is the definition.
(Peru is a country)
'pure form' is the wordplay.
'form' indicates anagramming the letters (another form of the letters).
'pure' anagrammed gives 'PERU'.
'of' acts as a link.
(Other definitions for peru that I've seen before include "South American country" , "Machu Picchu country" , "Country of Lima, Cuzco and Paddington Bear" , "Homeland of Paddington Bear" , "Nazca, Cuzco here" .)