Definitions for "Dead key"
On some non-English keyboards, a key that is used with another key to create an accented character. A dead key, when pressed, produces no visible character but indicates that the diacritic it represents is to be combined with the character produced by the next letter key pressed.
a key that does not produce a character
a key that generates a character, such as the umlaut (double-dot), that is combined with another character to form a composite character