Related Clues:

• It's often chewed in class
• It's removed for writing
• Writer's protection
• It prevents drying up
• Part of a Bic Cristal
• Montblanc topper
• Something removed before signing
• Ink saver
• Bic top
• Thing an anxious writer may chew
• Top removed before dashing off?
• Ballpoint topper
• Preventer of some shirt stains