a pre-defined character or characters used to do some internal or pre-defined action
The escape key is normally abbreviated to Esc. Pressing the escape key normally aborts the current procedure.
(n.) A keyboard key, usually labeled Esc, that, when pressed, cancels a window operation. Alternately, pressing the Escape key in combination with another key performs a specific keyboard function.
A key on a computer keyboard commonly used to escape from somewhere in a program or to go back one screen
n. A key on a computer keyboard that sends the escape (ESC) character to the computer. In many applications, the Escape key moves the user back one level in the menu structure or exits the program. See also Clear key.