barometer

Etymology

baro- + -meter

noun

1. An instrument for measuring atmospheric pressure.
2. (figurative, by extension) Anything used as a gauge or indicator.
   An election is not necessarily an accurate barometer of public opinion. There are other ways in which it makes itself felt, through the press, the forum, discussion, and through every other type of communication. 1916 Jun, Michigan Law Review, volume 14, number 8, pp. 661-665
   Italy’s 10-year yield spread versus Germany, considered a barometer of political and economic risks in the euro area, climbed as high as 1.9 percentage points on Tuesday, its widest since the early stages of the pandemic when investors dumped riskier eurozone government debt. 2022-05-04, Tommy Stubbington, Martin Arnold, “ECB policy tightening sends eurozone borrowing costs soaring”, in Financial Times
   Elections in six Malaysian states on Saturday will serve as a barometer of public sentiment for Prime Minister Anwar Ibrahim’s unity government against a powerful opposition consisting of Malay-Muslim political parties. 2023-08-10, “Owners of ‘LGBT’ Swatch watches could be jailed for three years in Malaysia”, in THe Guardian