flashboard

Noun

flashboard (plural flashboards)

1. (US) A board placed temporarily upon a dam, river, stream, etc. (typically within a permanent frame) to raise the water above its usual level.
   • A form of cheap open weir which has been commonly constructed in the West is the open wooden frame and flashboard weir.1909, Herbert Michael Wilson, Irrigation Engineering, page 168
   • The railing at the upstream side also serves as a guide and a support for the manually operated hoist for the flashboard placement and removal.1952, Tennessee Valley Authority, Design of TVA Projects: Civil and structural design, page 301
2. (broadly) A board that controls the flow of any material.
   • There exists a trapezoidal groove in the bottom of each container and a flashboard fixed in feeding system which match the groove.2010, Honghai Liu, Han Ding, Zhenhua Xiong, Intelligent Robotics and Applications, page 522
   • […] a flashboard is installed on the outer side of the rear wall to adjust and open-close the seed discharge hole, with the flashboard fastened with a wedge.2020, Jueming Hua, Lisheng Feng, Thirty Great Inventions of China, page 288
3. A sheet of material that is subjected to an electric pulse or flashover in order to produce plasma.
   • The plasma produced by the flashboard was mostly C⁺ and C⁺⁺.1990, B N Breizman, B A Knyazev, High-power Particle Beams, page 373
   • A polyethylene sheet (flashboard) is attached on the anode (aluminum), which acts as the ion source.2001, Digest of Technical Papers - Volume 13, page 1842
4. Any automated display that shows temporary information.
   • Thus encroaching telephone wires, angrily projecting one's arm, an overhanging flashboard, or tree, leaning walls, and overhanging roof, projecting eaves and the shooting of guns have all been regarded as invasions of the superincumbent airspace — the exclusive realm of the landownder.1957, The Journal of Air Law and Commerce - Volume 24, page 132
   • With the new flashboard, a good team could concentrate on one target at a time, even in fairly heavy firing .1972, Arthur R. Hercz, Development of the Field Artillery Observation, page 4
   1. An electronic display that shows the winning values in various gambling games such as keno or bingo.
      • The holder of a ticket that contains a match of all the numbers on any one of the Player's Cards to the numbers on the Flashboard card using the 48 Flashboard card numbers and the 49th and 50th Bonus Balls shall be entitled to a prize of $50.1996, Florida Administrative Weekly - Volume 22, Issues 47-52, page 7028
      • In the middle of the table, a roll-down hopper connected to a flashboard. Players bought cards from the dealer, then tried to roll a ball into the hopper in such a way that the flashboard would register a card of a suit and number that would match the cards the players had bought, filling in a...2003, Robert L. Shook, Jackpot!: Harrah's Winning Secrets for Customer Loyalty, page 9
5. An acrylic board used to display children's work in a school.
6. A board for displaying language material in the classroom, used like a flashcard but potentially holding more information.
   • Then he comes forward, takes the flashboard V, and stands in front of the class so that all may see it .1932, The Progressive Teacher, page 18
   • The tachistoscope is a mechanical flashboard, an apparatus for testing recognition, attention, and memory, which flashes images on a screen for measured periods of time, usually from 1/100 of a second to one second.1960, Louis Shores, Instructional Materials: An Introduction for Teachers
7. (historical) A device used in the 1920s for teaching typing skills which provided feedback on which key was pressed by lighting up the corresponding value.
   • There is a regular typewriter keyboard which is in mechanical connection with a scientifically designed, step by step "flashboard." The machine is designed to develop accurate typists through the realization of visual images.1921, Office Appliances; The Magazine of Office Equipment, page 16
   • This flashboard also is equipped with the standard layout of letters, signs, etc., each having a white spot under it, but which is conceled by a small shutter.1922 May, “Typewriter Students Aided By "Flashboard" Machine”, in Popular Mechanics, volume 37, number 5, page 696