| 1 | English | trainer | A person who trains another; a coach; A person... |
| 2 | English | train | Elongated portion; Connected sequence of people... |
| 3 | Middle English | train | — |
| 4 | Old French | train | a delay, a drawing out |
| 5 | Old French | traïner | Alternative form of trainer; to pull out, to draw |
| 6 | Vulgar Latin | traginare | present active infinitive of *traginō |
| 7 | Latin | tragēre | — |
| 8 | Latin | trahere | second-person singular future passive indicative... |
| 9 | Latin | traho | I drag, pull; I trail; I extract, withdraw |
| 10 | Proto-Italic | traɣō | — |
| 11 | Proto-Indo-European | tregʰ- | to drag, pull?; to run, walk |
| 12 | Proto-Indo-European | dʰregʰ- | to run |