Lactometer n. : An instrument for estimating the purity or richness of milk, as a measuring glass, a specific gravity bulb, or other apparatus.

Example:
What is a Lactometer and for what purpose and in what industry is it used?

Taxonomy
Lactometer, free encyclopedia, instrument, cream, search, Galactometer, richness, deposit, unadulterated, 1914, Personal tools, Interaction, Toolbox, Languages, non-profit organization, Reference Work, original article, en.wikipedia.

Defination from the web:
Lactometer. From Wikipedia, the free encyclopedia. Jump to: navigation, search. Lactometer or Galactometer, a simple instrument used in testing the richness of milk, is graduated into a hundred parts. ...