recurrent       
adjective uk/rɪˈkʌr.ənt/ us/rɪˈkɝː.ənt/
 反复出现的;再次发生的;重新产生的
happening again many times
  The patient has a two-month history of recurrent episodes of pancreatitis. 这位患者有两个月的胰腺炎复发病史。 
 The 'what ifs' of history is a recurrent theme in her writing. 历史的“假如…则…”是她小说中反复出现的主题。 
 Synonyms: perennial repeated