Grab a bit of air (6)
I believe the answer is:
snatch
This clue is a double definition.
'grab' is the first definition.
(I know that grab can be written as snatch)
'a bit of air' is the second definition.
(I've seen this before)
(Other definitions for snatch that I've seen before include "Piece of music" , "pluck" , "bit of air" , "weightlifting move" , "Dense clump of grass" .)