Begin a few airy moves (4,4)
I believe the answer is:
fire away
'begin' is the definition.
(fire away can mean to begin or start something)
'a few airy moves' is the wordplay.
'moves' indicates an anagram.
'a'+'few'+'airy'='afewairy'
'afewairy' is an anagram of 'FIRE AWAY'.
(Other definitions for fire away that I've seen before include "Make a start or go ahead - using guns?" , "Informally, go ahead with all guns blazing" , "Go ahead, begin" .)