Simple categories matching symmetric:

• polyhedron,
• pit,
• object,
• material,
• shape,
• function,
• surface,
• interface,
• part,
• structure,
• phase,
• crystal,
• form,
• processing,
• space,
• figure,
• center,
• site,
• loop,
• pattern,
• cell,
• container,
• window,
• system,
• polygon,

Members with property symmetric:

• cylinder,
• sphere,
• oval,
• supernova_remnant,
• bush,
• fractal,
• direct_approach,
• rectangular_pit,
• octagon,
• disk,
• equilateral,
• bell,
• cube,
• cone,
• daisy,
• erythrocyte,
• circular_cone,
• correlation_function,
• character,
• helical_spring,
• star,
• aspherical_surface,
• grid,
• hexagon,
• rib,
• conical_shape,
• ellipse,
• tank,
• circle,
• square,
• cylinder_grating,
• circular_cylinder,
• bubble,
• conical_surface,
• rectangle_window,
• holographic_grating,
• oxygen_site,
• u_center,
• comet,
• circular_diaphragm,
• regular_solid,
• rectangular_box,
• lense_mold,
• honey,
• molecule,
• pentagon,
• rna,
• square_structure,
• axle,
• coaxial_connector,
• inert-gas_atom,
• lithographic_setup,
• ionic_crystal,
• rectangle,
• ball,
• flat,
• complex,
• black_hole,
• smoke,
• plane,
• prism,
• surface,
• triangle,
• moon,
• crystalline_solid,
• anamorphic_surface,
• spherical_surface,
• fiber,
• optical_glasses,
• periodic_solid,
• bottle,
• triangle_function,
• ellipsis,
• ad_space,
• anamorphic_lense,
• cloud,
• spheroid,
• traveling-wave_devices,
• pillar,
• paraboloid_mirror,
• icosahedron,
• prolate_sphere,
• hyperbolic_space,
• ball_sphere,
• face,
• lampshade,
• pipe,
• torus,
• heptagon,
• wall_right,
• round_shape,
• windblown_bubble,
• gaussian_shape,
• liquid,
• turbine_blade,
• silicon,
• cap,
• loop_iteration,
• crystal,
• glasses,
• double_angle,
• right-angle_corner,
• isosceles_triangle,
• pen,
• square_tube,
• band,
• zinc,
• phase_plate,
• laser_mirror,
• round_peg,
• optical_fibre,
• spherical_particle,
• cup,
• small_molecule,
• variety,
• space,
• klystron,
• wheel,
• glass,
• biaxial_crystal,
• symmetric_cone,
• crescent,
• vase,
• finite_cylinder,
• spheroid_mirror,
• circle_fig,
• straight_wall,
• parity,
• gyroscope,
• polygon,
• ellipsoid,
• rectangular_prism,
• pressure_vessel,
• car,
• lightbulb,
• ophthalmic_lense,
• mushroom,
• disk_galaxy,
• pentagonal_rod,
• cu,
• degeneracy,
• hemisphere,
• liquid_surface,
• center,
• liquid_phase,
• ge,
• reentry_vehicle,
• rectangular_lamina,
• truncated_icosahedron,
• aspheric_surface,
• atom,
• des,