Main definitions of hydra in English

: hydra1Hydra2

hydra1

noun

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

    • ‘Roughly like a giant squid, or one of those micoscopic hydras, but blown up to immense proportions.’
    • ‘There are some animals that don't belong to the Bilateria, though: members of the phylum Cnidaria, the jellyfish, hydra, sea anemones, and corals, which are typically radially symmetric.’
    • ‘The same is true for hydra, a freshwater cnidarian.’
    • ‘The Phylum Cnidaria includes such diverse forms as jellyfish, hydra, sea anemones, and corals.’
    • ‘Several drawings depict forms that have the amorphous shapes of sea life such as hydras and jellyfish.’

Origin

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.

Pronunciation

hydra

/ˈhaɪdrə//ˈhīdrə/

Main definitions of hydra in English

: hydra1Hydra2

Hydra2

proper noun

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

    1. 1.1as noun hydra A thing which is hard to overcome or resist because of its pervasive or enduring quality or its many aspects.
      • ‘Database scalability is a many-headed hydra that's hard to define, let alone tame.’
      • ‘We might have to strike back at some heads on this terrorist hydra, try not to slaughter innocents, and swallow the collateral damage.’
      • ‘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.’
  • 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.

    Compare with Hydrus
    1. 2.1as genitive Hydrae /ˈhīdrē/ Used with preceding letter or numeral to designate a star in the Hydra constellation.
      ‘the star Beta Hydrae’

Origin

Via Latin from Greek hudra.

Pronunciation

Hydra

/ˈhaɪdrə//ˈhīdrə/