hydra

English Thesaurus

1. small tubular solitary freshwater hydrozoan polyp (noun.animal)

hypernym	:	hydroid, hydrozoan,
definition	:	colonial coelenterates having the polyp phase dominant (noun.animal)

member meronym	:	genus hydra,
definition	:	hydras (noun.animal)

2. trouble that cannot be overcome by a single effort because of its many aspects or its persistent and pervasive quality (noun.cognition)

hypernym	:	problem, trouble,
definition	:	a source of difficulty (noun.cognition)

3. a long faint constellation in the southern hemisphere near the equator stretching between Virgo and Cancer (noun.object)

instance hypernym	:	constellation,
definition	:	a configuration of stars as seen from the earth (noun.object)

4. (Greek mythology) monster with nine heads; when struck off each head was replaced by two new ones (noun.person)

hypernym	:	mythical creature, mythical monster,
definition	:	a monster renowned in folklore and myth (noun.person)

domain category	:	greek mythology,
definition	:	the mythology of the ancient Greeks (noun.group)