Ma*nom"e*ter (?), n. [Gr. &?; thin, rare + -meter: cf. F. manomètre.] An instrument for measuring the tension or elastic force of gases, steam, etc., constructed usually on the principle of allowing the gas to exert its elastic force in raising a column of mercury in an open tube, or in compressing a portion of air or other gas in a closed tube with mercury or other liquid intervening, or in bending a metallic or other spring so as to set in motion an index; a pressure gauge. See Pressure, and Illust. of Air pump.

• an instrument to measure pressure in a fluid
       *1973: Pökler helped in working out the Halbmodelle solution: bisecting the model lengthwise and mounting it flat-side to the wall of the test chamber, bringing the tubes through that way to all the manometers outside. — Thomas Pynchon, Gravity's Rainbow