Wall
A wall was an upright structure used by architects and shipbuilders for defining an area and carrying a load. A wall could be for security, shelter, soundproofing, or, simply, for decoration. Walls were made from many different kinds of material. A unique wall was the transparency which was made of a transparent material, making it a kind of wall-window.
Walls could be used to display artwork or trophies. Klingons, for example, would have their enemies' heads stuffed and mounted in their quarters. (TOS: "Obsession")
In the USS Enterprise, the phasers may have been able to cut through the walls. Some doors could be opened by cutting through the wall circuits adjacent to the door even if the mechanism was locked off. Walls inside the quarters and along some of the corridors had communicators in them which had the capability to record what was said. (TOS: "Wink of an Eye", "The Naked Time", "The Conscience of the King")
The walls of the Galaxy-class starships were made of tritanium. Replicators were mounted in walls, and the doors could open automatically when someone walked near them. There were also energy conduits within the walls, and polyduranide in the bulkheads. The walls of the turboshaft were equipped with ladders to allow movement within the shaft in the case the turbolift was unoperative. (TNG: "Where Silence Has Lease", "Up The Long Ladder", "Who Watches The Watchers", "Disaster")
Borg ships had compartments in the walls that housed two Borg each. (TNG: "Q Who")
The warp core had a reactor wall. If it got too hot, increasing intake of liquid helium could cool it. (TNG: "The Nth Degree")
In the 23rd century, intra-ship beaming (transporting from one section of the ship to another) was possible, but rarely done because it was so dangerous. Pinpoint accuracy was required, as rematerializing in a solid object, deck, or wall was deadly. (TOS: "Day of the Dove") By the 24th century, near-warp transport was possible, but could have unusual effects. For example, the individual being transported might perceive being "stuck" in a wall before the transport completed. (TNG: "The Schizoid Man")
Holodeck technology obscured the locations of the walls by projecting images of more distant perspectives, allowing the room to feel much larger than it was. One could, however, reveal the wall by personally touching it or by throwing an object at a location that did not appear to be a wall, such as a space between two trees. (TNG: "Encounter at Farpoint", "Elementary, Dear Data")
Walls could be used as cover against an explosion or other attack. (TOS: "A Taste of Armageddon")
Cells, the most basic unit of biology, had a structure protecting the rest of the cell components called a cell wall. Low cell wall integrity could make transmission of infectious agents impossible. (TNG: "Identity Crisis")
Caves could be formed by water or by volcanic activity. If the walls were dry, it might be an indication of the cave being formed by lava flows. (TNG: "Final Mission")
The allegorical Tamarian language had the phrase, "Shaka, when the walls fell," indicating a failure. (TNG: "Darmok")
As a method of intimidation or organization, individuals could be asked or instructed to line up against a wall. (TOS: "Patterns of Force")
"White walls" were a type of tire in the 20th century on Earth wherein the entirety or portion of the sidewall was made of white rubber instead of the uniform black. (TNG: "Clues")
"Climbing the walls" was an idiom to indicate someone had an excessive amount of energy, sometimes as an effect of drugs. (TOS: "By Any Other Name") "Putting it to the wall" was another idiom that indicated the pilot of a vehicle to go as fast as possible. (TNG: "Time Squared") A wall was also a metaphor that could be used to indicate social distance between two people. (TNG: "The Icarus Factor") To feel as if one's "back was to the wall" was to feel as if they were trapped. (TNG: "The Wounded") To be a "fly on the wall" was to watch proceedings silently as if the viewer were not there. (TNG: "A Matter Of Time")
Noonien Soong theorized that Humans valued old things like churches, walls, and antiques because they desired a sense of continuity to give their lives purpose. (TNG: "Brothers")
The people of Amerind had a legend which foretold the appearance of a god from the walls of their temple. (TOS: "The Paradise Syndrome")
The walls of the complex on Arret were unfamiliar to Commander Spock. However, they were much stronger and harder than anything he'd measured. (TOS: "Return to Tomorrow")
On Deneb IV, the tunnels beneath Farpoint Station were comprised of an unknown substance that Geordi La Forge had never seen before. (TNG: "Encounter at Farpoint")
On Earth, a 20th century periodical was the Wall Street Journal, named for a street named for its adjacency to an old wall. (TNG: "The Neutral Zone") The Earth children's rhyme Humpty Dumpty featured the titular Humpty Dumpty sitting on a wall until it fell off it. (TNG: "The Masterpiece Society")
Hortas could cut through walls to create tunnels in such a way that they would become hot. They might also use this ability to interfere with the structural integrity of adjacent cave walls. (TOS: "The Devil in the Dark")
Kelvans were creatures of space, and therefore did not appreciate the openness of planets. They preferred the constrictiveness of walls, considering them safe and comforting. (TOS: "By Any Other Name")
Part of the Legaran protocol involved bare walls of a muted tone. (TNG: "Sarek"
Some caves on Melona IV had monocaladium particulates in the walls. (TNG: "Silicon Avatar")
There was starithium ore in the walls of some caverns on Risa. (TNG: "Captain's Holiday")
On Rubicun III, forbidden areas were cordoned off with white walls or fences. Entering these zones was punishable by death. (TNG: "Justice")
When the planet Sarpeidon was about to be destroyed by the supernova of its star, the inhabitants created a time portal to escape destruction. Some of these portals were located in walls. (TOS: "All Our Yesterdays")
The Turkana IV colony fusion sources were located underground, and the source that powered defense systems could be access by entry points evenly spaced in the walls of the chamber below every twenty five meters. (TNG: "Legacy")
In 1836, during the Battle of the Alamo, the Mexican Army, under the command of Antonio López de Santa Anna, came over the north wall of the Alamo and defeated the defenders of the Alamo. Centuries later, when studying the battle by using a scale model of the Alamo compound, Julian Bashir considered reinforcing the north wall, the south wall, and any other place of the Alamo so as to keep the enemy out and give the defenders of the Alamo a chance of winning. (DS9: "The Changing Face of Evil")
The walls of the Council Chambers on Organia were very thick. (TOS: "Errand of Mercy")
On Capella IV, outside Capellan territory was a canyon that was difficult to escape. The walls of the canyon got progressively higher and narrower. (TOS: "Friday's Child")
When Captain James T. Kirk and the crew traveled to the year 1986, Montgomery Scott visited Plexicorp to obtain a plexiglass wall that could withstand the pressure of 18,000 cubic feet of water. The technology currently available at that time meant the wall would need to be six inches thick. Since the Scott required a thinner wall, he offered to show the plant's head, Nichols, how to manufacture a wall that would only be one inch thick. (Star Trek IV: The Voyage Home)
On Talos IV, the Talosians built their cells with transparencies. In 2254, when he was a captive, Captain Christopher Pike tested the strength of the transparency by throwing himself against it. (TOS: "The Cage")
In 2365, Nagilum created an illusion of the USS Yamato. The materials of its walls appeared to be beyond that of 24th century Federation ships. (TNG: "Where Silence Has Lease")
Later that year, Geordi La Forge characterized Sonya Gomez' frenetic energy and clumsiness as "banging into walls," warning that she wouldn't last long if she didn't relax. (TNG: "Q Who")