Simple categories matching singular:

• fluid,
• point,
• structure,
• control,
• object,
• interaction,
• prey,
• event,
• characteristic,
• pattern,
• effect,
• state,
• operator,
• set,
• region,
• shape,
• product,
• source,
• movement,
• measure,

Members with property singular:

• core,
• vortex_center,
• corner,
• crash,
• edge,
• machine_hours,
• herring,
• volcanic_eruption,
• taste,
• chemical_attribute,
• vertex,
• delta_point,
• cusp,
• real_pole,
• core_point,
• focus_point,
• branch_point,
• crack_tip,
• comet_shower,
• home_purchase,
• step_edge,
• local_storm,
• flexion,
• incarnation,
• cod,
• crack,
• resurrection,
• fault,
• node_point,
• contact_point,
• tangential_point,
• boundary,
• pole,
• bifurcation_point,
• storm,
• triple_point,
• singular_musical,
• surface_interaction,
• umbilical_point,
• asian_tsunami,
• triangle_shape,
• peak_flow,
• death,
• sydney_opera,
• angular_point,
• step,
• dirac_measure,
• frame,
• flood,
• animal,
• critical_point,
• wave-front_dislocation,
• column,
• assassination,
• leaf_pattern,
• space_utilization,
• bra,
• short_coaching,
• fold_point,
• vortex,
• principal_line,
• award_show,
• disruption,
• merger,
• glasses,
• pollock,
• stent_end,
• coalescence,
• color,
• war,
• miracle,
• accident,
• earth,
• point,
• crossing,
• south,
• contact_line,
• impact,
• personal_injury,
• mute_point,
• solution_set,
• relative_minimum,
• fall,
• acquisition,
• interface_edge,
• parade,
• blackout,
• plane_crash,
• equatorial_sheet,
• zero,
• concert,
• valve,
• local_minimum,
• doughnut_pattern,
• statue,
• butterfly_state,
• area,
• transition_state,
• source,
• hostage_situation,
• tone,
• terrorist_activity,
• work_duration,
• ridge_ending,
• slavery,
• mortgage_crisis,
• corner_point,
• center_point,
• projection,
• inflection_point,
• discontinuity_front,
• tree,
• peak,
• contradictory_information,
• video,
• reentrant_corner,
• mackerel,
• asymmetric_division,
• stock-market_crash,
• assault,
• large_order,
• specimen_tree,
• class,
• audio,
• discontinuity,
• image,
• saddle_point,
• minimum,
• trouser,
• tube,
• black_identity,
• star,
• network,
• saddle,
• origin,
• dislocation,
• vehicular_damage,
• band_edge,
• road,
• water,
• number,
• vacation,
• sharp_corner,
• text,
• workshop,
• book,
• parental_divorce,
• pump,
• undulation,
• circular_shape,
• text_box,
• extremum,
• branching_point,
• long_crack,
• building,
• squid,
• flare,
• switch,
• plant,
• percussion,
• asteroid_strike,
• distortion,
• maximum,
• ridge_break,
• wedge_state,
• notch_tip,
• rise,
• l_shape,