Those folk, hard to miss, quietly spoken, and not around for long (8)
I believe the answer is:
temporal
'not around for long' is the definition.
(only temporary)
'those folk hard to miss quietly spoken' is the wordplay.
'those folk' becomes 'them' (I've seen this in another clue).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to miss' is a deletion indicator.
'quietly' becomes 'p' (p for piano and quiet).
'spoken' becomes 'oral' (similar in meaning).
'them' with 'h' taken away is 'tem'.
'tem'+'p'+'oral'='TEMPORAL'
'and' acts as a link.
(Other definitions for temporal that I've seen before include "on the Head's side?" , "about the side of the head" , "Worldly, secular" , "Passing" , "Earthly" .)