Related Clues:

• First of three O's, perhaps
• -- Tac (breath mint)
• Start of a grid game
• Habitual spasm
• Small spasmodic reaction
• Automatic response
• Quirky habit
• Muscle jerk
• Nervous mannerism
• Start of a grid-based game
• Opening in "Hollywood Squares," essentially
• "___-Tac-Dough" (quiz show)
• First X, potentially
• ___ Tac (breath freshener)
• "Twitch," minus every other letter