Related Clues:

• Unthinking response from judge supported by classic law
• Nervous spasm
• Action not requiring conscious thought
• Mark said to be such a jerk
• Convulsion brought on by insect, it's said
• Half the heart's movement that's subconscious
• Knee-jerk
• Facial muscle spasm
• Not too big a jerk
• Square one?
• Mo's audible nervous habit
• Constantly twirling a lock of hair, e.g
• Involuntary (action)
• Responsive
• - - action