Source : Webster's Revised Unabridged Dictionary (1913)

Gravimeter \Gra*vim"e*ter\, n. [L. gravis heavy + -meter: cf. F.
   gravim[`e]tre.] (Physics)
   An instrument for ascertaining the specific gravity of
   bodies.

Source : WordNet®

gravimeter
     n 1: a measuring instrument for determining the specific gravity
          of a liquid or solid [syn: {hydrometer}]
     2: a measuring instrument for measuring variations in the
        gravitational field of the earth [syn: {gravity meter}]