Hydra vs. Octopus — What's the Difference?

Trouble that cannot be overcome by a single effort because of its many aspects or its persistent and pervasive quality;

Octopus (pl. octopuses, see below for variants) are soft-bodied, eight-limbed molluscs of the order Octopoda (, ok-TOP-ə-də).

Greek Mythology The many-headed monster that was slain by Hercules.

Any of various carnivorous marine cephalopod mollusks chiefly of the family Octopodidae, having a soft body, eight arms with suckers, a large distinct head, and a mouth with a strong beak.

(Astronomy)A satellite of Pluto.

Something, such as a multinational corporation, that has many powerful, centrally controlled branches.

A constellation in the equatorial region of the southern sky near Cancer, Libra, and Centaurus. Also called Snake2.

Any of several marine molluscs of the family Octopodidae, having no internal or external protective shell or bone (unlike the nautilus, squid and cuttlefish) and eight arms each covered with suckers.

A persistent or multifaceted problem that cannot be eradicated by a single effort.

(uncountable) The flesh of these marine molluscs eaten as food.

Any of several small solitary freshwater hydrozoans of the genus Hydra and related genera, having a cylindrical body and a mouth surrounded by tentacles.

An organization that has many powerful branches controlled from the centre.

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.

To put (or attempt to put) one's fingers, hands or arms in many things or places at roughly the same time.

(fantasy) A dragon-like creature with many heads and the ability to regrow them when maimed.

To spread out in long arms or legs in many directions.

A complex, multifarious problem or situation that cannot be solved easily and rapidly.

To plug a large number of devices into a single electric outlet.

A serpent or monster in the lake or marsh of Lerna, in the Peloponnesus, represented as having many heads, one of which, when cut off, was immediately succeeded by two others, unless the wound was cauterized. It was slain by Hercules. Hence, a terrible monster.

(by extension) To grow in use vastly beyond what was originally intended.

Hence: A multifarious evil, or an evil having many sources; not to be overcome by a single effort.

To hunt and catch octopuses.

Any small fresh-water hydroid of the genus Hydra, usually found attached to sticks, stones, etc., by a basal sucker.

To behave like an octopus.

A southern constellation of great length lying southerly from Cancer, Leo, and Virgo.

A genus of eight-armed cephalopods, including numerous species, some of them of large size. See Devilfish.

(Greek mythology) monster with nine heads; when struck off each head was replaced by two new ones;

Any member of the genus Octopus.

A long faint constellation in the southern hemisphere near the equator stretching between Virgo and Cancer

Something resembling an octopus in having numerous controlling arms or branches that reach widely and influence many activities; - used mostly of organizations, such as diversified corporations.

Small tubular solitary freshwater hydrozoan polyp

Tentacles of octopus prepared as food

Bottom-living cephalopod having a soft oval body with eight long tentacles