The Collaborative International Dictionary of English v.0.48:
Galvanometer \Gal`va*nom"e*ter\, n. [Galvanic + -meter: cf. F.
An instrument or apparatus for measuring the intensity of an
electric current, usually by the deflection of a magnetic
Differential galvanometer. See under Differental, a.
Sine galvanometer, Cosine galvanometer, Tangent
galvanometer (Elec.), a galvanometer in which the sine,
cosine, or tangent respectively, of the angle through
which the needle is deflected, is proportional to the
strength of the current passed through the instrument.