'Variometer' definitions:

Definition of 'variometer'

(from WordNet)
noun
A measuring instrument for measuring variations in a magnetic field

Definition of 'Variometer'

From: GCIDE
  • Variometer \Va`ri*om"e*ter\, n. [L. varius various + -meter.] (Elec.) An instrument for comparing magnetic forces, esp. in the earth's magnetic field. [Webster 1913 Suppl.]