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noun \ˈwȯl\

Simple Definition of wall

  • : a structure of brick, stone, etc., that surrounds an area or separates one area from another

  • : the structure that forms the side of a room or building

  • : the outer layer of something that is hollow (such as a part of the body or of a plant)

Source: Merriam-Webster's Learner's Dictionary

Full Definition of wall

  1. 1 a :  a high thick masonry structure forming a long rampart or an enclosure chiefly for defense —often used in plural b :  a masonry fence around a garden, park, or estate c :  a structure that serves to hold back pressure (as of water or sliding earth)

  2. 2 :  one of the sides of a room or building connecting floor and ceiling or foundation and roof

  3. 3 :  the side of a footpath next to buildings

  4. 4 :  an extreme or desperate position or a state of defeat, failure, or ruin <the surrounded troops had their backs against the wall>

  5. 5 :  a material layer enclosing space <the wall of a container> <heart walls>

  6. 6 :  something resembling a wall (as in appearance, function, or effect); especially :  something that acts as a barrier or defense <a wall of reserve> <tariff wall>

wall–like play \ˈwȯl-ˌlīk\ adjective
off the wall
  1. slang :  crazy <the plan was off the wall>

up the wall
  1. slang :  into a state of intense agitation, annoyance, or frustration <the noise drove me up the wall>

Examples of wall in a sentence

  1. A stone wall marks off their property.

  2. the Great Wall of China

  3. the walls of the ancient city

  4. She hung posters on the walls of her room.

  5. This apartment building has thin walls, and you can hear everything your neighbors say.

  6. Muscles in the abdominal wall help protect organs.

Origin of wall

Middle English, from Old English weall; akin to Middle High German wall; both from Latin vallum rampart, from vallus stake, palisade; perhaps akin to Old Norse vǫlr staff — more at wale

First Known Use: before 12th century

Other Civil Engineering Terms




Definition of wall

  1. transitive verb
  2. 1 a :  to provide, cover with, or surround with or as if with a wall <wall in the garden> b :  to separate by or as if by a wall <walled off half the house>

  3. 2 a :  immure <walled the monster up within the tomb — E. A. Poe> b :  to close (an opening) with or as if with a wall

13th Century

First Known Use of wall

13th century

Other Building Terms




Definition of wall

of the eyes

  1. intransitive verb
  2. :  to roll in a dramatic manner

  3. transitive verb
  4. :  to roll (one's eyes) in a dramatic manner

Origin of wall

Middle English (Scots) wawlen, probably from Middle English wawil- (in wawil-eghed walleyed)

First Known Use: 15th century

WALL Defined for Kids



noun \ˈwȯl\

Definition of wall for Students

  1. 1 :  one of the sides of a room or building

  2. 2 :  a solid structure (as of stone) built to enclose or shut off a space <The property is surrounded by a brick wall.>

  3. 3 :  something that separates one thing from another <a wall of mountains>

  4. 4 :  a layer of material enclosing space <the heart wall> <the wall of a pipe>

walled \ˈwȯld\ adjective




Definition of wall for Students


  1. :  to build or have a wall in or around

Medical Dictionary


noun \ˈwȯl\

Medical Definition of wall

  1. :  a structural layer surrounding a cavity, hollow organ, or mass of material <molecules small enough to be absorbed through the intestinal wall—Josie Glausiusz> <muscles of the abdominal wall>

walled \ˈwȯld\play adjective

Seen and Heard

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expressing little or no emotion

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