Hydra

n 1: (Greek mythology) monster with nine heads; when struck off

each head was replaced by two new ones; "Hydra was slain

by Hercules" [syn: {Hydra}]

2: a long faint constellation near the equator stretching

between Virgo and Cancer [syn: {Hydra}, {Snake}]

3: small tubular solitary freshwater hydrozoan polyp