fireworm

/ˈfaɪərˌwɜrm/
noun
  1. A type of marine worm that has bristles that can cause a burning or stinging sensation when touched.
    • The diver was careful not to touch the bright red fireworm on the coral.
    • Fireworms are often found in warm ocean waters near reefs.
    • A sting from a fireworm can be very painful and cause a rash.
  2. A glowworm or insect larva that produces light, sometimes called a firefly larva.
    • In some regions, people call firefly larvae fireworms.
    • A fireworm's light is a chemical reaction inside its body.
    • The children collected fireworms in a jar to watch them glow at night.