Noun
keycap (plural keycaps)
The part of a key (on a keyboard) that is pressed by the user, as opposed to any electromechanical unit underneath.
There are very few single legend keycaps, as expected on this 60% keyboard since real estate is precious, and the top center of the keycap on those that are present hints towards where the LEDs underneath have been put. Source: Internet
All I needed was a single keycap. Source: Internet