Very ardent to convert to green (7)
I believe the answer is:
verdant
'green' is the definition.
(I've seen this in another clue)
'very ardent to convert' is the wordplay.
'very' becomes 'v' (abbreviation).
'to convert' is an anagram indicator (I've seen 'converts' mean this).
'ardent' anagrammed gives 'erdant'.
'v'+'erdant'='VERDANT'
'to' is the link.
(Other definitions for verdant that I've seen before include "Leafy" , "Unsophisticated" , "Rather green" , "Covered with lush green grass or vegetation" , "Having green growth" .)