pacemaker Meaning, Definition & Usage

1. noun a leading instance in its field
   pacesetter.
   
   • the new policy will be a pacesetter in community relations
2. noun a specialized bit of heart tissue that controls the heartbeat
   cardiac pacemaker; SA node; sinoatrial node.
   
3. noun an implanted electronic device that takes over the function of the natural cardiac pacemaker
   artificial pacemaker.
   
4. noun a horse used to set the pace in racing
   pacer; pacesetter.
   

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