1. The plural of luminousness; the quality or state of being luminous; the property of emitting or reflecting light brightly.
Usage: Plural form; typically used in technical, scientific, or formal contexts when referring to multiple instances or types of luminous qualities.

Examples

• The luminousnesses of different phosphorescent materials were compared in the laboratory.
• The artist studied the various luminousnesses of the gemstones to select the most brilliant ones.
• The luminousnesses of the deep-sea creatures fascinated the marine biologists.
• We measured the luminousnesses of the paint samples under ultraviolet light.
• The luminousnesses of the stars vary greatly depending on their distance and composition.