Dictionary.com

hydra

[ hahy-druh ]
/ ˈhaɪ drə /
Save This Word!

noun, plural hy·dras, hy·drae [hahy-dree] /ˈhaɪ dri/ for 1-3, genitive hy·drae [hahy-dree] /ˈhaɪ dri/ for 4.
(often initial capital letter)Classical Mythology. a water or marsh serpent with nine heads, each of which, if cut off, grew back as two; Hercules killed this serpent by cauterizing the necks as he cut off the heads.
any freshwater polyp of the genus Hydra and related genera, having a cylindrical body with a ring of tentacles surrounding the mouth, and usually living attached to rocks, plants, etc., but also capable of detaching and floating in the water.
a persistent or many-sided problem that presents new obstacles as soon as one aspect is solved.
(initial capital letter)Astronomy. the Sea Serpent, a large southern constellation extending through 90° of the sky, being the longest of all constellations.
QUIZ
SPRINT TO THE FINISH WITH THIS OLYMPICS QUIZ!
Compete in our Olympics quiz to see if you can take home the gold medal in Olympics knowledge.
Question 1 of 10
Where was the Olympics first held?
Meet Grammar CoachWrite or paste your essay, email, or story into Grammar Coach and get grammar helpImprove Your Writing
Meet Grammar CoachImprove Your Writing
Write or paste your essay, email, or story into Grammar Coach and get grammar help

Origin of hydra

First recorded in 1325–75; from Latin hydra, from Greek hýdrā “water serpent” (replacing Middle English ydre, from Middle French, from Latin); see otter
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

How to use hydra in a sentence

British Dictionary definitions for hydra (1 of 3)

hydra
/ (ˈhaɪdrə) /

noun plural -dras or -drae (-driː)
any solitary freshwater hydroid coelenterate of the genus Hydra, in which the body is a slender polyp with tentacles around the mouth
a persistent trouble or evilthe hydra of the Irish problem

Word Origin for hydra

C16: from Latin, from Greek hudra water serpent; compare otter

British Dictionary definitions for hydra (2 of 3)

Hydra1
/ (ˈhaɪdrə) /

noun
Greek myth a monster with nine heads, each of which, when struck off, was replaced by two new ones

British Dictionary definitions for hydra (3 of 3)

Hydra2
/ (ˈhaɪdrə) /

noun Latin genitive Hydrae (ˈhaɪdriː)
a very long faint constellation lying mainly in the S hemisphere and extending from near Virgo to Cancer
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for hydra

hydra
[ hīdrə ]

Plural hydras hydrae (drē)
See under hydroid.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK