1904, from speed + -meter. A Germanic-Greek hybrid and thus much execrated.
[T]he ancient Greeks & Romans knew what speed was, & yet no-one supposes they called it speed, whence it follows that speedo- & speedometer are barbarisms. [Fowler]
The correct classical formation is tachometer.
实用例句
1. The speedometer showed that we were doing 50 miles per hour.
计速表显示我们的时速是50英里.
来自《简明英汉词典》
2. The speedometer was rocking between 60 and 65.
速度表在60至65之间摆动着.
来自《简明英汉词典》
3. The instrument that measures the speed is a speedometer.
用来测定速度的仪器是速度计.
来自辞典例句
4. You can define the excessive speed of your motor - car by a speedometer.