Greek character vocalises thoughts (7)
I believe the answer is:
musings
'thoughts' is the definition.
(musing is a kind of thought)
'greek character vocalises' is the wordplay.
'greek character' becomes 'mu' (letter from the Greek alphabet).
'vocalises' becomes 'sings' (I've seen this in another clue).
'mu'+'sings'='MUSINGS'
(Other definitions for musings that I've seen before include "dreams" , "Thoughts" .)