Whole tree in unusual state (6)
I believe the answer is:
entire
'whole' is the definition.
(similar in meaning)
'tree in unusual state' is the wordplay.
'tree in' anagrams to 'ENTIRE'.
However, I am not sure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for entire that I've seen before include "in one piece" , "Lure" , "outright" , "Unharmed - total" , "Full and complete" .)