HYDRA
- a freshwater polyp [n HYDRAE, HYDRAS]
- a persistent or many-sided problem that presents new obstacles as soon as one aspect is solved.
- serpent with nine heads, each of which, if cut off, grew back as two
- any freshwater polyp, esp. of the genus Hydra, having a cylindrical body, tentacles around the mouth, and usually attached to a rock or plant
- the Sea Serpent
- a many-headed serpent or monster in Greek mythology that was slain by Hercules and each head of which when cut off was replaced by two others
- multifarious evil not to be overcome by a single effort
- southern constellation of great length that lies south of Cancer, Sextans, Corvus, and Virgo and is represented on old maps by a serpent