Magnetometer \Mag`net*om"e*ter\, n. [Magneto- + -meter: cf. F. magn['e]tom[`e]tre.]

(Physics) An instrument for measuring the intensity of magnetic forces; also, less frequently, an instrument for determining any of the terrestrial magnetic elements, as the dip and declination.

Source: Webster's Revised Unabridged Dictionary (1913)