Modifiers matching difficulty:

• stable,
• emotional,
• unexpected,
• psychological,
• legal,
• chronic,
• physical,
• serious,
• underlying,
• related,
• personal,
• acute,
• neuropsychiatric,
• practical,
• prevalent,
• stressful,
• interpersonal,
• perceptual,
• significant,
• technical,
• psychiatric,
• mechanical,
• conceptual,
• leaning,
• single,
• respiratory,
• regulation,
• extraneous,
• past,
• unusual,
• unforeseen,
• financial,
• domestic,
• behavioural,
• structural,
• educational,
• severe,
• progressive,
• subjective,
• basic,
• functional,
• persistent,
• developmental,
• nutritional,
• minor,
• home,
• everyday,
• typical,
• possible,
• social,
• maternal,
• internal,
• spiritual,
• mental,
• logistical,
• neurological,
• commercial,
• smaller,
• motor,
• special,
• habitual,
• extreme,
• ongoing,
• mathematical,
• reproductive,
• academic,
• local,
• invisible,
• clinical,
• parental,
• external,
• extra,
• behavioral,
• sexual,
• common,
• secondary,
• important,
• surgical,
• visual,
• concurrent,
• experienced,
• technological,
• experimental,
• economic,
• periodic,
• environmental,
• hormonal,
• somatic,
• cognitive,
• particular,
• natural,
• temporary,
• administrative,
• operational,
• real,
• traditional,
• anatomical,
• linguistic,
• unanticipated,
• computational,
• major,
• sensory,

Simple categories matching serious:

• imperfection,
• illness,
• disease,
• title,
• circumstances,
• consequence,
• sanction,
• infection,
• procedure,
• gathering,
• science,
• endeavor,
• crime,
• damage,
• condition,
• challenge,
• calamity,
• abnormality,
• disorder,
• abuse,
• infraction,
• manifestation,
• sin,
• evil,
• information,
• weapon,
• injury,
• sickness,
• matter,
• stimulant,
• offense,
• offence,
• defect,
• professional,
• substance,
• event,
• morbidity,
• help,
• conduct,
• passion,
• trauma,
• work,
• phobia,
• ceremony,
• pathology,
• trait,
• problem,
• violence,
• wound,
• promise,
• std,
• state,
• assault,
• stage,
• infringement,
• piece,
• felony,
• threat,
• happening,
• enterprise,
• drug,
• contagion,
• act,
• document,
• discipline,
• trouble,
• charge,
• symptom,
• mishap,
• misdeed,
• study,
• occurrence,
• theme,
• topic,
• malfunction,
• malady,
• business,
• casualty,
• hazard,
• content,
• case,
• reader,
• failure,
• error,
• effort,
• harm,
• ailment,
• song,
• end,
• phenomenon,
• form,
• stuff,
• behaviour,
• aberration,
• game,
• difficulty,
• works,
• agent,
• profession,
• risk,
• journal,
• conflict,
• development,
• injustice,
• penalty,
• point,
• zoonosis,
• subject,
• animal,
• user,
• complication,
• program,
• material,
• action,
• disaster,
• story,
• reaction,
• attempt,
• pain,
• participation,
• constraint,
• emotion,
• flaw,
• tumour,
• cancer,
• danger,
• addiction,
• misconduct,
• wrongdoing,
• behavior,
• attack,
• pains,
• malignancy,
• occasion,
• disturbance,
• need,
• setback,
• entity,
• malpractice,
• interaction,
• storm,
• tendency,
• diversion,
• virus,
• idea,
• application,
• indiscipline,
• experience,
• handicap,
• arrhythmia,
• grounds,
• complaint,
• violation,
• enjoyment,
• intervention,
• result,
• disability,
• forum,
• disruption,
• allergy,
• system,
• drama,
• status,
• mistake,
• situation,
• blemish,
• loss,
• narcotic,
• operation,
• issue,
• incident,
• misfortune,
• tale,
• nature,
• writing,
• bacteria,
• headache,
• item,
• misbehaviour,
• activity,
• accident,
• thing,
• larceny,
• cause,
• upheaval,
• music,
• scholar,
• harassment,
• measure,
• delinquent,
• transgression,
• surgery,
• dance,
• pathogen,
• sector,