periodical [ˌpɪriˈɑ:dɪkl]

例句:

• She made periodical visits to her dentist.
  她定期去看牙医。
  
• The quarterly magazine is a periodical published every three months.
  季刊是每3个月出版一次的期刊.
  
• They have already put out a new periodical.
  他们已经出版了一种新的期刊.
  
• A periodical...with which you may or may not be familiar.
  来自R. Macaulay
• The CCD is most probably related to periodical Sun activity.
  来自SA
• Periodical cicadas Planet Earth The biggest insect emergence on the planet.
  来自BBC