Envious but inexperienced (5)
I believe the answer is:
green
This clue is a double definition.
'envious' is the first definition.
(thesaurus)
'inexperienced' is the second definition.
(similar in meaning)
'but' acts as a link.
(Other definitions for green that I've seen before include "Genre (anag.)" , "Party label" , "Unripe; environmentalist" , ""Go" signal" , "Envious -- environmentalist" .)