pac·er /ˈpesɚ/
  步測器
  pac·er /ˈpesɚ/ 名詞
  起搏器,調搏器
  pa·cer n. One who, or that which, paces.
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  pacer
       n 1: a horse used to set the pace in racing [syn: pacemaker, pacesetter]
       2: a horse trained to a special gait in which both feet on one
          side leave the ground together