Source : Webster's Revised Unabridged Dictionary (1913)

Densimeter \Den*sim"e*ter\, n. [L. densus dense + -meter: cf. F.
   densim[`e]tre.]
   An instrument for ascertaining the specific gravity or
   density of a substance.

Source : WordNet®

densimeter
     n : a measuring instrument for determining density or specific
         gravity [syn: {densitometer}]