Related Clues:

• Line in 11 Across, e.g.
• "Didn't mean to open that" key
• Line in Anglo-Saxon, say
• "Exit full screen" button
• High key?
• Key for exiting a slideshow
• "Close this window" key
• Key hit in panic
• Key for closing a window?
• Key part of an exit strategy?
• Key to exit a program
• "Close this pop-up" key
• Keyboard key that exits full-screen mode
• Key left of F1
• "Cancel" PC key