Related Clues:

• Part of three-in-a-row
• Bing's pal
• Nervous habit
• Sudden spasm
• Quiver
• Certain X or O
• Half a mint?
• Head movement
• X-X-X part
• ___ Tacs (breath mints)
• 25-Down's other half
• Facial twitch
• Muscle movement
• Seek apples, perhaps
• First ''O'' of O-O-O