D defs.my
Entry 3 senses Webster, 1913

pacemaker

· IPA /ˈpeɪsˌmeɪkəɹ/
01 n. a specialized bit of heart tissue that controls the heartbeat.
  1. 1.
    a specialized bit of heart tissue that controls the heartbeat.(Physiol. & Anat.)
  2. 2.
    An implanted electronic device that takes over the function of the natural cardiac pacemaker{1}; -- used to assist people whose heartbeat is irregular.
  3. 3.
    A horse used to set the pace in racing.
Syn. cardiac pacemaker, sinoatrial node. — Syn. -- artificial pacemaker. — Syn. -- pacer, pacesetter.