Uneven breath each time produces throb (9)
I believe the answer is:
heartbeat
'throb' is the definition.
(thesaurus)
'uneven breath each time' is the wordplay.
'uneven' indicates anagramming the letters.
'each' becomes 'ea'.
'time' becomes 't'.
'breath' is an anagram of 'heartb'.
'heartb'+'ea'+'t'='HEARTBEAT'
'produces' acts as a link.
(Other definitions for heartbeat that I've seen before include "Essential pulsation" , "Circulation noise" , "Animating force" , "Pulse of cardiac origin" .)