"Take a __ breath" (4)
'take a breath' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for respire that I've seen before include "Breathe, exhale" , "Breathe in reprise" .)
(Other definitions for deep that I've seen before include "hard to understand" , "hard to follow" , "profoundly" , "Profound - cunning - sea - bass" , "Extending far down" .)