Related Clues:

• First X or O
• First O
• Odd habit
• A kind of twitch
• A little jerk?
• ''___ Tac Dough'' (game show)
• It's often played before playing
• First 'O'?
• Fixation
• Country song?
• X or O, in a game
• Uncontrollable movement
• Habitual jerk
• Super Bowl starter
• First of three O's, perhaps