shield

noun

1. a broad piece of armor, varying widely in form and size, carried apart from the body, usually on the left arm, as a defense against swords, lances, arrows, etc.
2. a similar device, often of lightweight plastic, used by riot police to protect themselves from rocks and other thrown objects.
3. something shaped like a shield, variously round, octagonal, triangular, or somewhat heart-shaped.
4. a person or thing that protects.
5. a police officer’s, detective’s, or sheriff’s badge.
6. Ordnance. a steel screen attached to a gun to protect its crew, mechanism, etc.
7. Mining. a movable framework for protecting a miner from cave-ins, etc.
8. Electricity. a covering, usually made of metal, placed around an electric device or circuit in order to reduce the effects of external electric and magnetic fields.
9. Zoology. a protective plate or the like on the body of an animal, as a scute, enlarged scale, etc.
10. dress shield.
11. Heraldry. an escutcheon, especially one broad at the top and pointed at the bottom, for displaying armorial bearings.
12. (initial capital letter) Astronomy. the constellation Scutum.
13. Also called continental shield. Geology. a vast area of ancient crustal rocks which, together with a platform, constitutes a craton.
14. a protective barrier against nuclear radiation, especially a lead or concrete structure around a reactor.

verb (used with object)

15. to protect (someone or something) with or as if with a shield.
16. to serve as a protection for.
17. to hide or conceal; protect by hiding.
18. Obsolete. to avert; forbid.

verb (used without object)

19. to act or serve as a shield.

noun

1. any protection used to intercept blows, missiles, etc, such as a tough piece of armour carried on the arm
2. any similar protective device
3. Also called: scutcheon, escutcheon heraldry a pointed stylized shield used for displaying armorial bearings
4. anything that resembles a shield in shape, such as a prize in a sports competition
5. the protective outer covering of an animal, such as the shell of a turtle
6. physics a structure of concrete, lead, etc, placed around a nuclear reactor or other source of radiation in order to prevent the escape of radiation
7. a broad stable plateau of ancient Precambrian rocks forming the rigid nucleus of a particular continentSee Baltic Shield, Canadian Shield
8. short for dress shield
9. civil engineering a hollow steel cylinder that protects men driving a circular tunnel through loose, soft, or water-bearing ground
10. the shield informal
    1. Australian short for the Sheffield Shield
    2. NZ short for the Ranfurly Shield

verb

11. (tr) to protect, hide, or conceal (something) from danger or harm

n.Old English scield, scild “shield; protector, defense,” literally “board,” from Proto-Germanic *skelduz (cf. Old Norse skjöldr, Old Saxon skild, Middle Dutch scilt, Dutch schild, German Schild, Gothic skildus), from *skel- “divide, split, separate,” from PIE root *(s)kel- (1) “to cut” (see scale (n.1)). Perhaps the notion is of a flat piece of wood made by splitting a log. Shield volcano (1911) translates German Schildvulkan (1910). Plate tectonics sense is from 1906, translating Suess (1888). v.Old English gescildan, from the root of shield (n.). Related: Shielded; shielding. Cf. German scilden. n.

1. A protective device or structure, such as a lead sheet to protect an individual from x-rays.

1. A wall or housing of an absorbing material, such as concrete or lead, built around a nuclear reactor to prevent the escape of radiation.
2. A structure or arrangement of metal plates or mesh designed to protect a piece of electronic equipment from electrostatic or magnetic interference.
3. A large geographic area where rocks of a continent’s craton (the ancient, relatively undisturbed portion of a continental plate) are visible at the surface. A shield is often surrounded by platforms covered with sediment.