barometer
/bəˈrɔmɪtə(r); bə`rɑmətɚ/ n
1 instrument for measuring atmospheric pressure, used esp for forecasting the weather 气压计, 睛雨表（尤用以预报天气）
The barometer is falling, ie Wet weather is indicated. 气压计在下降（表示天气潮湿）.
2 (fig 比喻) thing that indicates changes (in public opinion, market prices, sb's mood, etc) 显示（舆论、物价、人的情绪等的）变化的事物
a reliable barometer of public feeling 反映公众情绪的可靠的标志.