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shield (shēld)
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n.
1. A broad piece of armor made of rigid material and strapped to the arm or carried in the hand for protection against hurled or thrusted weapons.
2. A person or thing that provides protection.
3. A protective device or structure, as:
a. A steel sheet attached to an artillery piece to protect gunners from small-arms fire and shrapnel.
b. Physics A wall or housing of concrete or lead built around a nuclear reactor to prevent the escape of radiation.
c. Electronics A structure or arrangement of metal plates or mesh designed to protect a piece of electronic equipment from electrostatic or magnetic interference.
d. A pad worn, as at the armpits, to protect a garment from perspiration.
e. A sanitary napkin.
4. Zoology A protective plate or similar hard outer covering; a scute or scutellum.
5. Something that resembles a shield, as:
a. An escutcheon.
b. A decorative emblem that often serves to identify an organization or a government.
c. A police officer's badge.
6. Geology The ancient, stable, interior layer of continents composed of primarily Precambrian igneous or metamorphic rocks. Also called continental shield.
v. shield·ed, shield·ing, shields
v.tr.
1. To protect from being attacked, exposed to danger, or subjected to difficulty: "a policymaking elite whose families and purses are shielded from the sacrifices war entails" (Uwe E. Reinhardt). See Synonyms at defend.
2. To cover up; conceal: "Though many eyes were watching, none could pierce the halo of morning sunlight that surrounded and shielded the hawk" (Peter Dunne).
v.intr.
To act or serve as a shield or safeguard.

[Middle English sheld, from Old English scield; see skel-1 in the Appendix of Indo-European roots.]

shielder n.
(click for a larger image)
shield
Masai warrior with spear and shield

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 

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