Green maybe inclined to talk too much about beginning of revolution (6)
I believe the answer is:
grassy
'green' is the definition.
(I've seen this in another clue)
'maybe inclined to talk too much about beginning of revolution' is the wordplay.
'maybe inclined to talk too much' becomes 'gassy' (gas can mean to chat or talk).
'about' is an insertion indicator.
'beginning of' suggests taking the first letters.
The first letter of 'revolution' is 'r'.
'gassy' placed around 'r' is 'GRASSY'.
(Other definitions for grassy that I've seen before include "Like lawns or pasture" , "Naturally green?" .)