keycap

one of a set of covers for the individual keys on a computer keyboard, used decoratively or for some other purpose in place of those supplied by the manufacturer: What better way to spiff up your mechanical keyboard than to get a brand-new set of keycaps?

a cover for the head or wide top portion of the key to a lock, making the key easier to identify and to grip while turning in the lock: Our 4-pack of vinyl key caps includes one each in a variety of colors—for home, office, shed, or anything else you lock.