[1] : The Collaborative International Dictionary of English v.0.48

magnetometer \mag`netom"eter\, n. magneto- + -meter: cf. f.
   magn'etom`etre. 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.
   1913 webster

[2] : WordNet (r) 2.0

magnetometer
     n : a meter to compare strengths of magnetic fields syn: gaussmeter
see also:
gaussmeter 

Magnetometer >> M Words
Magnetometer, definition of term: Magnetometer
magnetometer_pag1.html