The Collaborative International Dictionary of English v.0.48:
Snail \Snail\ (sn[=a]l), n. [OE. snaile, AS. sn[ae]gel, snegel,
sn[ae]gl; akin to G. schnecke, OHG. snecko, Dan. snegl, Icel.
(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 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
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.
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, Medicago 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.