1. Plural of cnida; specialized stinging cells found in jellyfish, sea anemones, and other cnidarians, used to capture prey and defend against predators.
Usage: biology; technical; plural form

Examples

• Jellyfish use cnidae to paralyze small fish and plankton.
• The cnidae of sea anemones contain venom that helps them capture food.
• Under a microscope, cnidae appear as coiled, harpoon-like structures.
• When a swimmer touches a jellyfish, the cnidae discharge and cause a sting.
• Marine biologists study cnidae to understand how cnidarians hunt.