Meditation of Greek character sitting by grass (6)
I believe the answer is:
musing
'meditation' is the definition.
(synonyms)
'greek character sitting by grass' is the wordplay.
'greek character' becomes 'mu' (letter from the Greek alphabet).
'sitting by' says to put letters next to each other.
'grass' becomes 'sing' (both can mean to act as an informant).
'mu'+'sing'='MUSING'
'of' acts as a link.
(Other definitions for musing that I've seen before include "Absorbed in thought" , "reflection" , "Meditating" , "Cogitation" , "Reflecting or pondering" .)