Brief rush of wind (4)
I believe the answer is:
gust
'brief rush of wind' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for gust that I've seen before include "Burst of strong wind" , "A strong current of air" , "14 [OUTBURST]" , "Blast of air" , "Puff (of wind)" .)