1 train /ˈtreɪn/ noun
plural trains
1 train
plural trains
Learner's definition of TRAIN
: 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
[count] old-fashioned : a group of people, vehicles, or animals that are moving in a line see also wagon train
[count] : an orderly series of events, actions, or ideas
[count] technical : a series of moving machine parts (such as gears) for controlling motion
[count] : a part of a long dress that trails behind the woman who is wearing it see color picture on this page

in train

British, formal
: in an active state or condition
see also gravy train
2 train /ˈtreɪn/ verb
trains; trained; training
2 train
trains; trained; training
Learner's definition of TRAIN
[+ object] : to teach (someone) the skills needed to do something (such as a job) : to give instruction to (someone)
[no object] : to be taught the skills needed to do something (such as a job)
[+ object] : to cause (someone or something) to develop an ability or skill
[no object] : to try to make yourself stronger, faster, or better at doing something before competing in an event or competition
[+ object] : to help (someone) to prepare for an event or competition : to coach (an athlete)
[+ object] : to teach (an animal) to obey commands
see also house-train
[+ object] : to make (a plant) grow in a particular direction usually by bending, cutting, or tying it
[+ object] : to aim or point (something) toward something or in a particular direction

— trainable

/ˈtreɪnəbəl/ adjective [more trainable; most trainable]