1. The plural of metallicity; the abundance of heavy elements (metals) in a star or astronomical object, typically expressed as a ratio relative to the Sun.
Usage: astronomy; technical term

Examples

• Astronomers measure the metallicities of stars to understand their ages and origins.
• The metallicities of globular clusters reveal information about the early universe.
• Stars with different metallicities show distinct chemical compositions.
• High metallicities in a galaxy suggest active star formation over billions of years.
• The study compared metallicities across multiple stellar populations.