Snail, Snail, put out your horn,
I'll give you bread and barleycorns.

-- Traditional child's rhyme.

Generally speaking, a snail is a mollusk, class gastropodia*, of any of a number of families. They have a soft body covered by a shell. They are usually nocturnal. That's really all you can say on snails in general; 'snail' is not a very specific term. Annoyingly, this doesn't prevent people, even biologists, from using it as if it were a well-defined term.

Snails live all over the world, from the arctic to tropics. They come in all sorts of varieties. Many are edible, some are poisonous. Some bite, some give birth to live young. Amongst themselves, they contain all sorts of weirdness. They are often classified by the environment by which they live, salt-water, fresh-water, or on land. This is not a biological classification, but one of convenience.

Land snails: These snails have some specific adaptations so that they can live in a (comparatively) dry environment. They produce a layer of mucus to coat their bodies, helping keep the water in. This slime also helps them climb and hang on steep, even vertical, surfaces. Most land snails have lungs, but some manage with gills. Land snails have better eyesight in comparison to smell than do water-dwelling snails; connected to this, terrestrial snails have eye stalks.

  • The infamous French dish of escargot is a terrestrial snail of the family Helix.
  • Giant African Snails are often kept as pets (snails of the family Achatina). They can get over a foot long and weigh up to two pounds.

Fresh water snails: It's interesting to note that many fresh water snails actually have lungs, and must come to the surface to breath (for example, members of the families Lymnaeidae and Physidae). Many fresh water snails are actually descended from snails that had adapted to life on the land, and then moved back to the water. Some of these have re-developed gills, while others have not.

Us humans have a great interest in fresh water snails, because various species can carry the schistosomiasis parasite, a major health concern in areas of the world where indoor plumbing has not yet become common. We also like to use some species of fresh water snails for our aquariums (Apple snails, Trumpet snails and Ramshorn snails).

Marine snails: Salt-water snails are the largest group of snails, best known to the average human through the bright spiral shells that wash up on the shore. They are also harvested as food, particularly abalone and conch. Don't try gathering them yourself without reading up on the subject; some marine snails (family Conidae, genus Conus) secrete venom, which can be fatal to humans.

* Occasionally, the class of Gastropoda is said to consist of snails, indicating that, technically, slugs, limpets, and conchs are all types of snail.

And here's a little snail superstition, for the lonely noder. In the mid-1700s, young women (and perhaps men too) would set a (live) snail in the (cold) ashes of the fireplace, and watch its track. In theory, the snail's trail would resemble some letter, and that letter was the initial of one's future lover.

SNAFU principle = S = snail-mail

snail vt.

To snail-mail something. "Snail me a copy of those graphics, will you?"

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.

Snail (?), n. [OE. snaile, AS. sngel, snegel, sngl; akin to G. schnecke, OHG. snecko, Dan. snegl, Icel. snigill.]

1. Zool. (a)

Any one of numerous species of terrestrial air-breathing gastropods belonging to the genus Helix and many allied genera of the family Helicidae. They are abundant in nearly all parts of the world except the arctic regions, and feed almost entirely on vegetation; a land sanil.


Any gastropod having a general resemblance to the true snails, including fresh-water and marine species. See Pond snail, under Pond, and Sea snail.


Hence, a drone; a slow-moving person or thing.

3. Mech.

A spiral cam, or a flat piece of metal of spirally curved outline, used for giving motion to, or changing the position of, another part, as the hammer tail of a striking clock.


A tortoise; in ancient warfare, a movable roof or shed to protect besiegers; a testudo.


They had also all manner of gynes [engines] . . . that needful is [in] taking or sieging of castle or of city, as snails, that was naught else but hollow pavises and targets, under the which men, when they fought, were heled [protected], . . . as the snail is in his house; therefore they cleped them snails. Vegetius (Trans.).

5. Bot.

The pod of the sanil clover.

Ear snail, Edible snail, Pond snail, etc. See under Ear, Edible, etc. -- Snail borer Zool., a boring univalve mollusk; a drill. -- Snail clover Bot., a cloverlike plant (Medicago scuttellata, also, M. Helix); -- so named from its pods, which resemble the shells of snails; -- called also snail trefoil, snail medic, and beehive. -- Snail flower Bot., a leguminous plant (Phaseolus Caracalla) having the keel of the carolla spirally coiled like a snail shell. -- Snail shell Zool., the shell of snail. -- Snail trefoil. Bot. See Snail clover, above.


© Webster 1913.

Log in or register to write something here or to contact authors.