a group of vehicles that travel on a track and are connected to each other and usually to an engine : a connected group of railroad cars —often used before another noun
a group of people, vehicles, or animals that are moving in a line
an orderly series of events, actions, or ideas
2trainverb
to teach (someone) the skills needed to do something (such as a job) : to give instruction to (someone)
to be taught the skills needed to do something (such as a job)
to cause (someone or something) to develop an ability or skill