pycnometer
noun
pyc·nom·e·ter pik-ˈnä-mə-tər 
variants or pyknometer
: a standard vessel for measuring and comparing the densities of liquids or solids
Word History
Etymology
Greek pyknos + International Scientific Vocabulary -meter
First Known Use
1858, in the meaning defined above
Medical Definition
pycnometer
noun
pyc·nom·e·ter
variants or pyknometer
pik-ˈnäm-ət-ər
: a standard vessel often provided with a thermometer for measuring and comparing the densities or specific gravities of liquids or solids