Quite a while with the former (8)
I believe the answer is:
sometime
'former' is the definition.
(synonyms)
'quite a while' is the wordplay.
'quite a' becomes 'some' ('that's some car!' means 'that's quite a car!').
'while' becomes 'time' (I've seen this before).
'some'+'time'='SOMETIME'
'with the' acts as a link.
(Other definitions for sometime that I've seen before include "One day" , "On an undetermined date in the future" , "An indeterminate date in the future" , "On a future unnamed occasion" , "At an unknown moment" .)