Related Clues:

• Very tired
• Pooped, perhaps
• Wiped the slate clean
• No longer on the board
• Got rid of marks
• Shattered
• Cleared the board
• Cleaned, as a blackboard
• Physically and mentally fatigued
• Helped with the blackboard
• Bleeped out
• Wiped off
• Off the board
• No longer on tape
• Wiped off the blackboard