\Snail\ (sn[=a]l), n. [OE. snaile, AS. sn[ae]gel, snegel,
sn[ae]gl; akin to G. schnecke, OHG. snecko, Dan. snegl, Icel.
snigill.]
1. (Zo["o]l.)
   (a) Any one of numerous species of terrestrial
       air-breathing gastropods belonging to the genus Helix
       and many allied genera of the family {Helicid[ae]}.
       They are abundant in nearly all parts of the world
       except the arctic regions, and feed almost entirely on
       vegetation; a land snail.
   (b) Any gastropod having a general resemblance to the true
       snails, including fresh-water and marine species. See
       {Pond snail}, under {Pond}, and {Sea snail}.
2. 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.
4. A tortoise; in ancient warfare, a movable roof or shed to
   protect besiegers; a testudo. [Obs.]
         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} (Zo["o]l.), 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} (Zo["o]l.), the shell of snail.
{Snail trefoil}. (Bot.) See {Snail clover}, above.