A computer screen — visual display unit. This is the British version of the same office word as the American VDT, and the two mean the same thing. It belongs to the era of big shared computers, when a screen with a keyboard was a "unit" you sat at, connected to a machine elsewhere in the building. British workplace rules from the 1980s and 1990s are full of it: how far your eyes should be from the VDU, how often you should look away, whether your employer must pay for your eye test. Some British health-and-safety paperwork still says VDU today, which is why it has lasted a little better than VDT — the law kept the word alive after ordinary speech dropped it. In normal conversation, nobody says it; say screen or monitor. A learner should be able to read it without stopping, and should recognise that it is not a different piece of equipment from the screen they already know. Say it letter by letter: vee-dee-you.

（電腦）顯示器、螢幕（英式舊稱，多見於職業安全法規）