ba·rom·e·ter 
(bə-rŏmĭ-tər)
(bə-rŏmĭ-tər)n.
1. An instrument for measuring atmospheric pressure, used especially in weather forecasting.
2. Something that registers or responds to fluctuations; an indicator: Opinion polls serve as a barometer of the public mood.
bar′o·metric (băr′ə-mĕtrĭk), bar′o·metri·cal adj.
bar′o·metri·cal·ly adv.
ba·rome·try n.