Related Clues:

• __-tac-toe
• Little spasm
• First of a game trio
• Knee jerk, e.g.
• First X or O
• First O
• Odd habit
• A kind of twitch
• A little jerk?
• ''___ Tac Dough'' (game show)
• First 'O'?
• Fixation
• X or O, in a game
• Uncontrollable movement
• Habitual jerk