1 [singular, uncountable] the process of teaching or being taught the skills for a particular job or activity [↪ train]COLLOCATIONS 
give somebody training receive/undergo training a training course/programme/session a training session a training manual (=a book you use in training) on-the-job training (=while doing a job rather than in a classroom) in-service training (=while working for an employer rather than at college etc) teacher training (=training you do to become a teacher) staff/management training basic training (=the first training that a soldier receives)

give somebody training receive/undergo training a training course/programme/session a training session a training manual (=a book you use in training) on-the-job training (=while doing a job rather than in a classroom) in-service training (=while working for an employer rather than at college etc) teacher training (=training you do to become a teacher) staff/management training basic training (=the first training that a soldier receives)
2 [uncountable]DSO physical exercises that you do to stay healthy or prepare for a competition [↪ train]:
Lesley does weight training twice a week.
Lesley does weight training twice a week.