Excessively craving grass after good year (6)
I believe the answer is:
greedy
'excessively craving' is the definition.
'grass after good year' is the wordplay.
'grass' becomes 'reed' (I've seen this before**).
'after' means one lot of letters go next to another.
'good' becomes 'g' (abbreviation).
'year' becomes 'y'.
'reed' put after 'g' is 'greed'.
'greed'+'y'='GREEDY'
(Other definitions for greedy that I've seen before include "Starving" , "Keen" , "Gluttonous" , "pig!" , "Avaricious and acquisitive" .)