Noun
overscan (uncountable)
(television) The additional area around the four edges of a video image, outside of the safe area, that is not normally seen by the viewer.
When connected to a normally-adjusted TV or monitor, the QL's video output would overscan horizontally. Source: Internet
This makes the display 320 or 640 pixels wide without overscan. Source: Internet
Vertical resolution, without overscan, is 200 pixels for an 60 Hz NTSC Amiga or 256 for a 50 Hz PAL Amiga. Source: Internet