n.[C]

1. 指示者；指示物[+that]
   The foreign minister's visit can be taken as one more indicator that the relationships between the two countries are improving.

   外長的訪問可以被看作是又一個信號，說明兩國關係在改善。

2. （儀器上的）指針，指示器；（車輛上的）變向指示燈
3. 【機】壓力計；示功器
4. 【化】指示劑
5. 【生】（說明環境狀況的）指示生物（群落）
6. 指標

n.

1. a thing that indicates a state or level.
2. a gauge or meter of a specified kind.
3. Brit. a flashing light on a vehicle to show that it is about to change lanes or turn.
4. Brit. an information board or screen in a railway station, airport, etc.
5. Chemistry  a compound which changes colour at a specific pH value or in the presence of a particular substance, and can be used to monitor a chemical change.