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.-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.-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.-the pod of the sanil clover.