Pro said grass is blue? (7)
I believe the answer is:
forlorn
'grass is blue?' is the definition.
I can't tell whether this defines the answer.
'pro said' is the wordplay.
'pro' becomes 'for' (I've seen this before).
'said' becomes 'lorn' (I can't explain this - if you can you should believe this answer much more).
'for'+'lorn'='FORLORN'
Can you help me to learn more?
(Other definitions for forlorn that I've seen before include "Forsaken" , "Wretched" , "Miserable" , "Pitifully sad and lonely" , "Left alone and unhappy" .)