Tree-huggers fine revolutionary, unfortunately (6)
I believe the answer is:
koalas
'tree-huggers' is the definition.
I can't judge whether this definition defines the answer.
'fine revolutionary unfortunately' is the wordplay.
'fine' becomes 'ok' (synonyms).
'revolutionary' shows that the letters should be reversed in order (letters revolve around).
'unfortunately' becomes 'alas' ('alas' is used to express regret).
'ok' backwards is 'ko'.
'ko'+'alas'='KOALAS'
Can you help me to learn more?
(Other definitions for koalas that I've seen before include "Australian arboreal marsupials" , "Tailless Australian marsupials" , "Tree-climbing marsupials in Australia" , "Australian tree-climbing marsupials" , "Australian tree-climbing mammals" .)