Simple categories matching abrupt:

• structure,
• variation,
• motion,
• fault,
• change,
• disturbance,
• feature,
• event,

Members with property abrupt:

• station_relocation,
• lane_narrowing,
• twist,
• airframe_vibration,
• crack,
• gait_disturbance,
• component_failure,
• vibration,
• component,
• storm,
• shutdown,
• plosive_burst,
• steps,
• shock,
• step_change,
• polarization_fluctuation,
• oil_embargo,
• step,
• environmental_shift,
• sharp_spike,
• psychotic_break,
• voltage_spike,
• intrusion,
• withdrawal,
• ridge,
• burst,
• inappropriate_response,
• slope,
• temperature_rise,
• confusion,
• volcanic_eruption,
• strong_storm,
• sharp_ridge,
• overhang,
• disaster,
• severe_flood,
• species_invasion,
• severe_storm,
• fishery_collapse,
• localised_area,
• extinction,
• level_shift,
• historic_preservation,
• bifurcation,
• conflict,
• motor_failure,
• voice_onset,
• tsunami,
• then_fault,
• revolution,
• land_price,
• wetting,
• landslide,
• glacial_termination,
• civil_war,
• losses_due,
• bolide_impact,
• spike,
• fault,
• introduction,
• rod,
• hormonal_readjustment,
• saccade,
• issue,
• damage,
• flood,
• deregulation,
• traffic_process,
• step_function,
• american_withdrawal,
• electrostatic_discharge,