barometer
noun [ C ] uk/bəˈrɒm.ɪ.tər/ us/bəˈrɑː.mə.t̬ɚ/
气压计
a device that measures air pressure and shows when the weather is likely to change
（显示特定形势或人们对某一问题态度变化的）晴雨表，标志
something that can show how a particular situation is developing, or how people's opinions on a particular matter are changing
This survey is considered to be a reliable barometer of public opinion. 这项调查被看作是可靠的晴雨表，能反映民意。