Frost develops around eastern wood (6)
I believe the answer is:
forest
'wood' is the definition.
(I know that wood can be written as forest)
'frost develops around eastern' is the wordplay.
'develops' indicates an anagram.
'around' means one lot of letters goes inside another.
'eastern' becomes 'e'.
'frost' is an anagram of 'forst'.
'forst' enclosing 'e' is 'FOREST'.
(Other definitions for forest that I've seen before include "Large, densely-wooded area" , "Best Actor Oscar winner 2006, for 'The Last King of Scotland'" , "that has branches everywhere" , "Sherwood or Pine, say" , "large area covered with trees" .)