Category Nuances for null:

• hard,
• flat,
• dense,
• concrete,
• inclined,
• nearby,
• vertical,
• rigid,
• fixed,
• irregular,
• costly,
• outside,
• adjacent,
• elevated,
• external,
• physical,
• visible,
• set,
• raised,
• aggregate,
• bumpy,
• paved,
• horizontal,
• light,
• incidental,
• hazardous,
• hidden,
• commercial,
• ancillary,
• difficult,
• important,
• unpainted,
• uneven,
• miscellaneous,
• narrow,
• challenging,
• exterior,
• public,
• structural,
• urban,
• smaller,
• conventional,
• stationary,
• low,
• immovable,
• permanent,
• delicate,
• straight,
• everyday,
• impervious,
• related,
• continuous,
• minor,
• structured,
• exposed,
• driving,
• porous,
• inanimate,
• rough,
• under,
• safe,

Simple Categories for null:

• surface,
• means,
• strip,
• appurtenance,
• structure,
• works,
• facility,
• object,
• fixture,
• ground,
• edge,
• installation,
• conveyance,
• equipment,
• work,
• job,
• unit,
• item,
• thing,
• placement,
• control,
• way,
• system,
• location,