re ‧ train /ˌriːˈtreɪn/ BrE AmE verb [intransitive and transitive]
[ Word Family: noun : ↑ trainee , ↑ trainer , ↑ training , ↑ retraining ; verb : ↑ train , ↑ retrain ; adjective : trained ≠ ↑ untrained ]
to learn or to teach someone the skills that are needed to do a different job:
One solution is to retrain the long-term unemployed.
retrain as
She’s hoping to retrain as a teacher.
—retraining noun [uncountable]