noun
: a crystalline salt MgF 2 occurring naturally as sellaite but also made synthetically and used chiefly as a flux and as a coating for optical glass to cut down reflection
noun
: a crystalline salt MgF 2 occurring naturally as sellaite but also made synthetically and used chiefly as a flux and as a coating for optical glass to cut down reflection
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012