Related Clues:

• "Do not ___!" (math-chalkboard directive)
• 'DO NOT ___' (chalkboard plea)
• Dry-___ board
• Rub out because put in before
• Rub off a blackboard
• Cancel Times (electronic)
• Remove from a DVD player
• Clear in class, maybe
• Correct, as a written mistake
• Wipe slate clean in takeover as expected
• Correct a pencil error
• Begin to correct
• Button whose icon consists of a triangle over a horizontal line
• Clear, as a computer's memory
• Fighter pilot's bailout button