timekeeper [ˈtaɪmˌkipɚ]

例句:

• The factory timekeeper keeps account of the hours of work done.
  工厂出勤时间计时员记录工作的时间.
  
• Officials include a referee, judges and a timekeeper.
  裁判人员包括一名台上裁判员 、 若干台下评判员和一名计时员.
  
• This clock is a good timekeeper.
  这钟是一个很好的计时器.
  
• Just as Dorothy learns from the smart Scarecrow, Milo learns from Tock's timekeeper's knowledge.
  来自NEWYORKER
• She is the timekeeper, and she is counting down a 10-minute handstand for a group of young gymnasts.
  来自NPR