refresher
noun [ C ] uk/rɪˈfreʃ.ər/ us/rɪˈfreʃ.ɚ/
（尤指为练习和提高长期不用的技能而上的）进修课程
a course to practise and improve skills, especially because you have not used them for a long time
I went on a refresher course on new techniques in design to bring myself up to date. 我参加了新设计技巧进修课程，以使自己跟上最新形势。