A frame or rounded plate made of wood, metal, hide, or leather, carried by warriors on the arm or in the hand, as a defense, from remote antiquity until the perfection of firearms rendered it more an encumbrance than a safeguard, and by savage peoples to the present day.Anything that protects or is used as a protection.A fender-plate attached to the share of a corn-plow to prevent clods from rolling on to the young plants.In zoology:A protective or defensive plate, buckler, or cuirass, of some determinate size, shape, or position; a scute, scutum, or scutellum; a lorica; a carapace: as, the shields or bucklers of a ganoid fish; the shields of a turtle, an armadillo, etc. See cuts under carapace, leaf-roller, scale, armadillo, and coluber.Some part, place, or mark likened to a shield; a thyroid formation. See cut under larynx.In dressmaking, a piece or strip of some repellent fabric used to protect a dress from mud, perspiration, etc.: as, a skirt-shield; an arm-shield.Figuratively, a shelter, protection, or defense; a bulwark.In botany, any flat, buckler-like body that is fixed by a stalk or pedicel from some part of the under surface, as the apothecium in certain lichens. (See apothecium.)In heraldry:The shield-shaped escutcheon used for all displays of arms, except when borne by women and sometimes by clergymen. See escutcheon and lozenge.A bearing representing a knightly shield.A French crown (in French, écu), so called from its having on one side the figure of a shield.The semi-transparent skin of the sides of a boar-pig, which is of considerable thickness, affording shield-like protection against the attacks of an adversary: apparently used formerly to furnish a shield for burlesque or mimic contests.A breed of domestic pigeons, of which there are four varieties, black, red, blue, and silver.More properly, a mantlet or wooden bulwark for crossbowmen and the like.To protect, defend, or shelter from danger, calamity, distress, annoyance, or the like: as, to shield one from attack; to shield one from the sun; to shield a criminal.To ward off.To forfend; forbid; avert.To act or serve as a shield; be a shelter or protection.n. n. A guard placed over or in front of rapidly moving machinery, especially over cutters such as saws and planes, to protect the workmen from accidents.n. A guard placed around belting where it passes through a floor, or around gears to prevent clothing of workmen or passers-by from becoming entangledn. A covering over bearings and shafts of grinding machinery to keep grit and dust from working into the contact-surfaces.n. A guard placed on an exposed shaft, and turning loosely with it, to prevent injury from accidental contact with the revolving mass.