Woodland in east in grip of nasty frost (6)
I believe the answer is:
forest
'woodland' is the definition.
('forest' can be a synonym of 'woodland')
'east in grip of nasty frost' is the wordplay.
'east' becomes 'e' ('E' can be a synonym of 'east').
'in grip' indicates putting letters inside.
'of nasty' indicates an anagram (I've seen 'nasty' mean this).
'frost' anagrammed gives 'forst'.
'e' going inside 'forst' is 'FOREST'.
'in' acts as a link.
(Other definitions for forest that I've seen before include "green area" , "large area covered with trees" , "Large area of trees and undergrowth" , "Large area of woodland" , "eg Sherwood" .)