Secure present for fan (6)
I believe the answer is:
winnow
'for fan' is the definition.
(winnowing is a kind of fanning)
'secure present' is the wordplay.
'secure' becomes 'win' (I've seen this in another clue).
'present' becomes 'now' (both can mean the current period).
'win'+'now'='WINNOW'
(Other definitions for winnow that I've seen before include "Dehusk grain using air currents" , "Blow air through (grain) to remove chaff" , "Separate chaff from grain" , "Sift out" , "Separate the wheat from the chaff" .)