- A serpent or monster in the lake or marsh of Lerna, in the
Peloponnesus, represented as having many heads, one of which, when cut
off, was immediately succeeded by two others, unless the wound was
cauterized. It was slain by Hercules. Hence, a terrible monster. - Hence: A multifarious evil, or an evil having many sources;
not to be overcome by a single effort. - Any small fresh-water hydroid of the genus Hydra, usually
found attached to sticks, stones, etc., by a basal sucker. - A southern constellation of great length lying southerly
from Cancer, Leo, and Virgo.
Meaning of 'hydra' (Princeton's WordNet)
1 . hydra
[ n]
Meaning (1): - (Greek mythology) monster with nine heads; when struck off each head was replaced by two new ones
Example in sentence:
Hydra was slain by Hercules
Meaning (2): - trouble that cannot be overcome by a single effort because of its many aspects or its persistent and pervasive quality
Example in sentence:
we may be facing a hydra that defies any easy solution