Pycnometers

Part of speech: noun

Definitions

1. An instrument designed for measuring the density of liquids by comparing their mass to the mass of an equal volume of water
2. A scientific device used to determine the specific gravity of a substance by assessing its buoyancy in a calibrated volume of liquid
3. A laboratory apparatus that assesses the density of liquids by weighing a known volume and comparing it to water under controlled conditions

Etymology: "Pycnometers" is the plural of "pycnometer", a device for measuring the density of a liquid or solid by filling a precisely known volume and weighing it. The name is built from two Ancient Greek elements: "puknos", meaning "dense" or "thick", and "metron", meaning "measure". Put together, the name says simply what the instrument does. The "pycno-" part keeps the Greek word for density-related thickness, and it appears in other scientific coinages such as "pycnic", used of a stocky body build. The "-meter" ending is the same Greek "metron" found in thermometer, barometer and speedometer, so the instrument's name follows the standard pattern for measuring devices.