hydra Definition

hydra
noun hydras, hydrae

1. A freshwater polyp with a tube-like body and tentacles round the mouth, remarkable for its ability to multiply when cut or divided.
2. Any manifold or persistent evil.
3. Greek mythol.
A water-monster with many heads, each of which when cut off was immediately replaced by two more.
Form: Hydra
4. astron.
A large southern constellation.
Form: Hydra

Etymology: 14c: from Greek hydor water.