manometer (n.)

"instrument for determining and indicating the elastic pressure of gases or vapors," 1730, from French manomètre (1706), said to have been coined by French mathematician Pierre Varignon (1654-1722) from Greek manos "thin, rare; loose in texture, porous; scanty, few" (from PIE root *men- (4) "small, isolated") + -mètre (see -meter). Related: Manometric; manometrical; manometrically.