Breathing in desire (10)
I believe the answer is:
aspiration
This clue is a double definition.
'breathing' is the first definition.
(thesaurus)
'desire' is the second definition.
(aspiration is a kind of desire)
'in' is the link.
(Other definitions for aspiration that I've seen before include "Ambition" , "Dream" , "With which to announce Hammers' first" , "Craving" , "goal" .)