hydrometer
noun
hy·drom·e·ter hī-ˈdrä-mə-tər 
: an instrument for determining the specific gravity of a liquid (such as battery acid or an alcohol solution) and hence its strength
hydrometric
ˌhī-drə-ˈme-trik
adjective 
Example Sentences
Recent Examples on the Web At 6 or 7 p.m., Schmitz and his family will check the syrup with a spoon and with a hydrometer — an instrument for measuring sugar content, Schmitz said. 
Tyler Langan, Milwaukee Journal Sentinel, 11 Apr. 2018 That includes tools such as the hydrometer, containers to ferment and age, yeast, preservatives and, of course, the grapes. Carolyn Wilke, sacbee, 1 Aug. 2017 From scientific gadgets like the hydrometer, used to measure the density of sugar in liquids, to practical concerns like empty bottles, Maryland Homebrew is packed. Kit Waskom Pollard, Howard County Times, 3 May 2017
Tyler Langan, Milwaukee Journal Sentinel, 11 Apr. 2018 That includes tools such as the hydrometer, containers to ferment and age, yeast, preservatives and, of course, the grapes. Carolyn Wilke, sacbee, 1 Aug. 2017 From scientific gadgets like the hydrometer, used to measure the density of sugar in liquids, to practical concerns like empty bottles, Maryland Homebrew is packed. Kit Waskom Pollard, Howard County Times, 3 May 2017 Word History
First Known Use
1675, in the meaning defined above
Medical Definition
hydrometer
noun
hy·drom·e·ter hī-ˈdräm-ət-ər
: an instrument for determining the specific gravity of a liquid (as an alcohol or saline solution) and hence its strength