Hydra in Czech

(Greek mythology) A mythological serpent with many heads, slain by Hercules as one of his twelve labours.

(constellation) A spring constellation of the northern sky, said to resemble a serpent. It lies just south of the zodiac and contains the star Alphard.

(constellation) A spring constellation of the northern sky, said to resemble a serpent. It lies just south of the zodiac and contains the star Alphard.

(biology) Any of several small freshwater polyps of the genus Hydra and related genera, having a naked cylindrical body and an oral opening surrounded by tentacles.