1. energy in the form of waves or particles emitted by radioactive substances or electromagnetic sources
Usage: physics; often used in plural form
2. the process of spreading outward from a central point
Usage: technical

Examples

• The nuclear plant monitors harmful radiations in the surrounding area.
• Solar radiations provide energy for photosynthesis in plants.
• The doctor ordered tests to check for exposure to dangerous radiations.
• Electromagnetic radiations include visible light and radio waves.
• The radiations from the heat source warmed the entire room.
• Scientists study cosmic radiations from distant stars.
• Medical equipment must be shielded from certain radiations.