Main definitions of hydra in English

: hydra1Hydra2


Pronunciation /ˈhīdrə/ /ˈhaɪdrə/

Translate hydra into Spanish


  • A minute freshwater coelenterate with a tubular body and a ring of tentacles around the mouth.

    Genus Hydra, class Hydrozoa


Via Latin from Greek hudra ‘water snake’ (see Hydra), named by Linnaeus because, if cut into pieces, each section can grow into a whole animal.

Main definitions of Hydra in English

: hydra1Hydra2


(also Hydrae)

Pronunciation /ˈhīdrə/ /ˈhaɪdrə/

Translate Hydra into Spanish

proper noun

  • 1Greek Mythology
    A many-headed snake whose heads grew again as they were cut off, eventually killed by Hercules.

  • 2Astronomy
    The largest constellation (the Water Snake or Sea Monster), said to represent the beast slain by Hercules. Its few bright stars are close to the celestial equator.


  • A thing that is hard to overcome or resist because of its pervasive or enduring quality or its many aspects.

    ‘his battle with the hydra of bureaucracy’
    • ‘Database scalability is a many-headed hydra that's hard to define, let alone tame.’
    • ‘Yet it appears that multi-headed hydra, our scientific research establishment, is pulling in more than 200 different directions.’
    • ‘There were very few studies on this multi-headed hydra so far.’
    • ‘And the wife in this two-headed hydra of nonsense claims to have a degree in biology.’


  • postpositive Used with preceding Greek letter or numeral to designate a star in the Hydra constellation.

    • ‘the star Beta Hydrae’


Via Latin from Greek hudra. Hydrae is the Latin genitive form of Hydra.