barometer
n. countablen. a tool that measures air pressure to help predict the weather. It can also mean anything that shows how a situation is changing or how people feel.
n. an instrument used to measure atmospheric pressure, primarily for weather forecasting and altitude determination. Figuratively, it refers to any indicator that reflects fluctuations in public opinion or social trends.
The barometer shows that the air pressure is falling.
Economists often view consumer spending as a reliable barometer of the country's overall financial health.
While the physical barometer indicated an approaching storm, the tense atmosphere in the boardroom served as a social barometer for the impending corporate restructuring.
From baro- + -meter. Coined in 1665 by Robert Boyle as a name for the instrument invented by Torricelli some 20 years earlier; soon thereafter borrowed from English into various languages.
Often used with the preposition 'of' when describing a figurative indicator.