an instrument for measuring the relative density of a liquid, usually consisting of a sealed graduated tube with a weighted bulb on one end, the relative density being indicated by the length of the unsubmerged stem
Derived forms
hydrometric (ˌhaɪdrəʊˈmɛtrɪk) or hydrometrical (ˌhydroˈmetrical)
adjective
hydrometrically (ˌhydroˈmetrically)
adverb
hydrometry (hyˈdrometry)
noun
hydrometer in American English
(haɪˈdrɑmətər)
noun
an instrument for measuring the specific gravity of liquids: it is a graduated, weighted tube that sinks in a liquid up to the point determined by the density of the liquid