Definition of "hydra" []

• 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. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The Governor of Adamawa State, Admiral Murtala Nyako (rtd.), has rated performance of the Nigerian press very high in recent years considering what he described as the hydra-headed challenges journalists encounter in the discharge of their duties."
• "Nothing in nature is immortal, but some clams can live centuries and a tiny freshwater creature called a hydra lives a very long time, at least until its pond dries up."
• "The next thing that he had done was to fight a battle with an ugly sort of monster, called a hydra, which had no less than nine heads, and exceedingly sharp teeth in every one."