火车头的英文：
train engine
locomotive

参考例句：

I'm afraid the engine will run off the rails.
我怕火车头要出轨了。

With a puff, a clang, and a clatter of rail it was gone.
火车头喷着烟，车轮隆隆转动，铁轨轰轰作响，于是这个地方就过去了。

An engine is coupled to a railway train
火车头与车厢挂在一起。

The train's nose resembles a kingfisher's beak.
火车头长得像翠鸟的喙。

I prefer to sit here, facing the engine.
我喜欢这儿，面对火车头。

He saw the locomotive bearing down on him.
他看见火车头向他压来。

I prefer to sit here, facing the engine.
我喜欢坐这儿，面对火车头。

The GM diesel engine shunted the coaches to Platform 4.
通用柴油动力火车头将车厢转轨到了 4 号月台。

For example, we called railroad engines iron horses and automobiles were labeled horseless carriages.
例如，我们曾把火车头称为“铁马”，把汽车称为“无马的马车”。

The whistle of the locomotive, more powerful than Amphion's lyre, was about to bid them rise from American soil
火车头的汽笛比神话中昂斐勇的七弦琴还要强，它使许多城市很快地在美洲大陆上冒出来了。

train是什么意思：
n. 火车；行列；顺序；后果；裙裾
v. 训练，锻炼，培养；修剪；瞄准；拖曳；乘火车

the tail of a train
火车的尾部

explosive train
火药系

Is this dog trained?
这狗受过排便训练吗？

engine是什么意思：
n. 发动机；引擎；火车头

He is an engineer.
他是位工程师。

The engine died.
引擎突然熄火了。

They are engineering a bridge.
他们正在建造一座桥。

locomotive是什么意思：
adj. 移动的，运动的
n. 机车；火车头

Of or relating to locomotion;locomotive.
运动的运动的或与运动有关的；能自己移动的

locomotive barn
机车车库

He is a locomotive engineer.
他是一名火车司机。