Blow the lighter stuff - succeed immediately (6)
I believe the answer is:
winnow
'blow the lighter stuff' is the definition.
'winnow' can be an answer for 'blow' (thesaurus). I am not certain of the 'the lighter stuff' bit.
'succeed immediately' is the wordplay.
'succeed' becomes 'win' (I've seen this in another clue).
'immediately' becomes 'now' (I've seen this in another clue).
'win'+'now'='WINNOW'
Can you help me to learn more?
(Other definitions for winnow that I've seen before include "Separate chaff from grain" , "Sift out" , "Dehusk grain using air currents" , "Separate the wheat from the chaff" , "Fan" .)