train

Concise Oxford English Dictionary © 2008 Oxford University Press:
train/treɪn/

▶verb

• 1 teach (a person or animal) a skill or type of behaviour through regular practice and instruction.

  ■ be taught in such a way.

• 2 make or become physically fit through a course of exercise and diet.

• 3 (train something on) point or aim something at.

• 4 cause (a plant) to grow in a particular direction or into a required shape.

• 5 dated go by train.

• 6 archaic entice (someone).

▶noun

• 1 a series of railway carriages or wagons moved as a unit by a locomotive or by integral motors.

• 2 a number of vehicles or pack animals moving in a line.

  ■ a retinue of attendants accompanying an important person.

• 3 a series of connected events or thoughts.

• 4 a long piece of trailing material attached to the back of a formal dress or robe.

• 5 a series of gears or other connected parts in machinery.

• 6 a trail of gunpowder for firing an explosive charge.

– phrases
in train in progress.
in the train of following behind.
in (or out of) training undergoing (or no longer undergoing) physical training for a sporting event.

■ physically fit (or unfit) as a result of this.

– derivatives
trainability noun,
trainable adjective,
training noun,
trainload noun.

– origin ME (as a noun in the sense ‘delay’): from OFr. train (masc.), traine (fem.), from trahiner (v.), from L. trahere ‘pull, draw’.