Respire and live having received new heart (7)
I believe the answer is:
breathe
'respire' is the definition.
(synonyms)
'live having received new heart' is the wordplay.
'live' becomes 'be' (synonyms).
'having received' indicates putting letters inside.
'new' indicates an anagram.
'heart' is an anagram of 'reath'.
'be' enclosing 'reath' is 'BREATHE'.
'and' acts as a link.
(Other definitions for breathe that I've seen before include "Take in 30" , "Respire - inspire - expire" , "Draw air into, and expel out of, the lungs" , "Absorb air" , "Take into mouth" .)