remedial  
adjective uk/rɪˈmiː.di.əl/ us/rɪˈmiː.di.əl/
  (TO IMPROVE)        
  formal补救的;纠正的;矫正的 
A remedial action is intended to correct something that is wrong or to improve a bad situation.
  to take urgent/immediate remedial action 采取紧急措施/立即采取行动进行补救 
 The bill requires owners to undertake remedial work on dilapidated buildings. 该法案规定房主应对其失修房屋进行修缮。 
  formal治疗的,医疗的 
Remedial exercises are intended to improve someone's health when they are ill.
   (EDUCATION)      
 [ before noun ] mainly UK(对有读写困难的人)补习的,辅导的 
relating to teaching that is intended to help people who have difficulties in reading or writing
  remedial classes/courses 补习班/课程 
 She is a teacher of remedial English. 她是英语补习班的老师。