Shield

A shield is a protective device, meant to intercept attacks. The term often refers to a device that is held in the hand, as opposed to armour and a bullet proof vest. The oldest form of shield was a protection used to block attacks by hand weapons and arrows. Such shields varied greatly in construction over time and place, and most civilizations made use of them. In Europe, shields were used in war up until the 17th century, when gunpowder powered weapons made shields obsolete in the battlefield. Shields for protection from armed attack is still used by many police forces around the world. Shields are sometimes used on artillery, as well.

In telecommunication, the term shield has the following meanings:

1. A housing, screen, sheath, or cover that substantially reduces the coupling of electric, magnetic, or electromagnetic fields into or out of circuits or transmission lines.

2. A protective cover that prevents the accidental contact of objects or persons with parts or components operating at hazardous voltage levels.

Source: from Federal Standard 1037C and from MIL-STD-188

In heraldry, the shield is the principal portion of a heraldic achievement or coat of arms. Figures and patterns are depicted emblazoned upon the shield in many different arrangements.

Other figures besides the shield are used; at one time ladies customarily bore their arms upon a lozenge, or diamond-shape, and clergymen bore theirs on a cartouche, or oval.

See also