train 
(trān)
(trān)n.
1. A series of connected railroad cars pulled or pushed by one or more locomotives.
2. A long line of moving people, animals, or vehicles.
3. The personnel, vehicles, and equipment following and providing supplies and services to a combat unit.
4. A part of a gown that trails behind the wearer.
5. A staff of people following in attendance; a retinue.
6.
a. An orderly succession of related events or thoughts; a sequence. See Synonyms at series.
b. A series of consequences wrought by an event; aftermath.
7. A set of linked mechanical parts: a train of gears.
8. A string of gunpowder that acts as a fuse for exploding a charge.
v. trained, train·ing, trains
v.tr.
1. To coach in or accustom to a mode of behavior or performance.
2. To make proficient with specialized instruction and practice. See Synonyms at teach.
3. To prepare physically, as with a regimen: train athletes for track-and-field competition.
4. To cause (a plant or one's hair) to take a desired course or shape, as by manipulating.
5. To point or direct (a gun or camera, for example) at something. See Synonyms at aim.
6. To let drag behind; trail.
v.intr.
1. To give or undergo a course of training: trained daily for the marathon.
2. To travel by railroad train.
[Middle English, trailing part of a gown, from Old French, from trainer, to drag, from Vulgar Latin *tragīnāre, from *tragere, to pull, back-formation from tractus, past participle of Latin trahere.]
train′a·bili·ty n.
traina·ble adj.