shield

American  

[sheeld] / ʃild /

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. Astronomy. Shield, 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.

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verb (used with object)

1. to protect (someone or something) with or as if with a shield.

2. to serve as a protection for.

3. to hide or conceal; protect by hiding.

4. Obsolete. to avert; forbid.

verb (used without object)

1. to act or serve as a shield.

shield British  

/ ʃiːld /

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 continent See 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. informal

    1. short for the Sheffield Shield

    2. short for the Ranfurly Shield

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verb

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

shield Scientific  

/ shēld /

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.

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Other Word Forms

• shielder noun
• shieldless adjective
• shieldlessly adverb
• shieldlessness noun
• shieldlike adjective
• undershield noun
• unshielded adjective
• unshielding adjective

Etymology

Origin of shield

First recorded before 900; (noun) Middle English shelde, Old English sceld; cognate with Dutch, German Schild, Gothic skildus; (verb) Middle English shelden, Old English sceldan, scildan, derivative of the noun

Explanation

A shield is a cover that protects whatever is behind or beneath it. If you carry a shield you might be a knight, or a traffic cop who likes to flash the badge. Ancestors of the word shield include the Old English scild, similar to sciell, or "shell," which suggests the meaning of the word. If you're a turtle, you might use your shell as a shield. But a shield doesn't have to be something physical. Philosopher Soren Kierkegaard once said, "Love is my sword, goodness my armor, and humor my shield." The word can also be used as a verb. You might shield your tender ears from hearing naughty words. Don't worry, shield is perfectly safe.

Example Sentences

He describes it as "a suit of armor," designed to shield the reactive center from water and other nearby molecules.

From Science Daily • Apr. 11, 2026

Engineers responded by changing the way the spacecraft re‑enters the atmosphere that simulations showed would reduce the thermal load on the shield.

From BBC • Apr. 11, 2026

That will set up the capsule to dive into the Earth’s atmosphere, putting to the test a heat shield designed to protect the ship and astronauts.

From The Wall Street Journal • Apr. 10, 2026

"We have high confidence in the system and the heat shield and the parachutes and the recovery systems we put together," Kshatriya said.

From Barron's • Apr. 10, 2026

It glances off a shimmering purple shield, though, and careens off to the side.

From "Kwame Crashes the Underworld" by Craig Kofi Farmer

Related Words

• conceal
• cover
• defend
• safeguard
• shelter