recurrence       
noun [ C or U ] uk/riˈkʌr.əns/ us/rɪˈkɝː.əns/
 反复出现;再次发生;重新产生
the fact of happening again
  The doctor told him to go to the hospital if there was a recurrence of his symptoms. 医生告诉他,如果症状复发的话就得去医院。 
 Maintaining immune function after surgery may contribute to lower tumour recurrence rates. 手术后保持免疫功能可能有助于降低肿瘤再发率。 
 Synonyms: repeat return