Five ranted about being green (7)
I believe the answer is:
Here is my best explanation:
'being green' is the definition.
'five ranted about' is the wordplay.
'five' becomes 'v' (roman numeral).
'about' indicates anagramming the letters.
'ranted' is an anagram of 'erdant'.
(Other definitions for verdant that I've seen before include "Green with vegetation", "Of grass or fields, green", "Unsophisticated", "Rather green", "Leafy", "Covered with lush green grass or vegetation", "Green like grass or fields", "Green, lush", "Lush, green" and "Having green growth".)