1. a chemical element that is essential for life and glows in the dark
2. any substance that glows without heat, especially when exposed to light

Examples

• Phosphorus is found in bones and teeth.
• Plants need phosphorus to grow properly.
• The match head contains red phosphorus.
• White phosphorus is highly toxic and flammable.
• The watch dial was painted with phosphorus so it would glow in the dark.
• Farmers add phosphorus fertilizer to improve crop yields.
• The scientist studied the properties of phosphorus compounds.