Quiet notion about atmosphere initially missing wine (5,4)
I believe the answer is:
pinot noir
'wine' is the definition.
(Pinot noir is an example)
'quiet notion about atmosphere initially missing' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'about' indicates anagramming the letters.
'atmosphere' becomes 'air' (synonyms).
'initially missing' means to remove the first letter.
'air' with its initial letter taken away is 'ir'.
'notion' anagrammed gives 'inotno'.
'p'+'inotno'+'ir'='PINOT NOIR'
(Other definitions for pinot noir that I've seen before include "Fruit" , "18 [WINE]" , "Wine grape variety" , "Red wine grape" , "Drink" .)