From Longman Dictionary of Contemporary Englishrefresher coursereˈfresher ˌcourse (also refresher /rɪˈfreʃə $ -ər/) noun [countable] SETa training course, usually a short one, that teaches you about new developments in a particular subject or skill, especially one that you need for your job
Examples from the Corpus
refresher course• In numerous training sessions, more than 50,000 people have had a refresher course on their community.• Or just need a refresher course on what goes into one?• For trainers or practising professionals needing a refresher course.• She had been on a refresher course.• a nursing refresher course• From now on all aircrew went through either a full conversion course or a short refresher course.From Longman Business Dictionaryrefresher coursereˈfresher ˌcourse a training course that teaches you about new developments in a particular subject or skill, especially one that you need for your jobNurses must attend a five-day refresher course every three years. → course 