From The Collaborative International Dictionary of English v.0.48 :
Manometer \Ma*nom"e*ter\, n. [Gr. ? thin, rare + -meter: cf. F.
manom[`e]tre.]
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.
[1913 Webster] Manometric
From WordNet (r) 3.0 (2006) :
manometer
n 1: a pressure gauge for comparing pressures of a gas