It could be sweet air, so to speak (2,2,4)
I believe the answer is:
as it were
'so to speak' is the definition.
(synonyms)
'it could be sweet air' is the wordplay.
'it could be' is an anagram indicator (the same letters could be an anagram).
'sweet'+'air'='sweetair'
'sweetair' with letters rearranged gives 'AS IT WERE'.
(Other definitions for as it were that I've seen before include "Seemingly" , "In a kind of way" , "So to speak" , "In sort of" , "you might say" .)