hydra meaning and definition

HYDRA noun

Definition of Hydra (noun)

1. (Greek mythology) monster with nine heads; when struck off each head was replaced by two new ones
   • "Hydra was slain by Hercules"
2. a long faint constellation in the southern hemisphere near the equator stretching between Virgo and Cancer
   • synonyms: Snake
3. trouble that cannot be overcome by a single effort because of its many aspects or its persistent and pervasive quality
   • "we may be facing a hydra that defies any easy solution"
4. small tubular solitary freshwater hydrozoan polyp