something that shows what a situation is like

Commodity prices can be a useful indicator of inflation, he claimed. 他声称，商品价格可以作为一种有用的通货膨胀指标。

an economic indicator 经济指标

one of the lights at the front and back of a road vehicle that flash to show which way the vehicle is turning

a device that shows a value or a change in level, speed, etc.

The car has an overhead console with a compass and outside temperature indicator. 这辆汽车上方有个仪表板，板上有个指南针和显示车外温度的指示器。