crown glass


crown glass
/ˈkraʊn glas/ (say 'krown glahs)

noun
1. an optical glass of low dispersion and generally low refractive index.
2. an old form of window glass formed by blowing a globe and whirling it into a disc, composed essentially of soda, lime, and silica; now used for decorative purposes.

Australian English dictionary. 2014.