Wonderful throw just missing opener (8)
I believe the answer is:
heavenly
'wonderful' is the definition.
(I've seen this before)
'throw just missing opener' is the wordplay.
'throw' becomes 'heave' (heave is a kind of throw).
'just missing opener' becomes 'nly' (I can't justify this - if you can you should believe this answer much more).
'heave'+'nly'='HEAVENLY'
Can you help me to learn more?
(Other definitions for heavenly that I've seen before include "Wonderful" , "Blissful" , "Celestial" , "Glorious" , "Divine" .)