Whole tree in unusual state (6)

I believe the answer is:

entire

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'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" .)

I've seen this clue in The Irish News.

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