Modifiers matching circumstance:

• unique,
• extreme,
• unforeseen,
• involuntary,
• unfortunate,
• severe,
• negative,
• unforeseeable,
• bad,
• extraordinary,
• exigent,
• relevant,
• historical,
• individual,
• threatening,
• unexpected,
• common,
• stressful,
• external,
• catastrophic,
• personal,
• special,
• exceptional,
• unusual,
• unavoidable,
• verifiable,

Simple categories matching involuntary:

• movement,
• measure,
• activity,
• act,
• termination,
• organs,
• action,
• reflex,
• situation,
• tissue,
• process,
• event,
• association,
• creditor,
• muscle,
• unemployment,
• exchange,
• cause,
• force,
• control,
• thing,
• response,
• departure,
• change,
• function,
• reaction,
• vocalization,
• emotion,
• motion,
• claim,
• circumstance,