Modifiers matching opening:

• natural,
• vertical,
• small,
• curved,
• smaller,
• narrow,
• off,
• necessary,
• outer,
• exterior,
• architectural,
• outside,
• surrounding,
• framed,
• structural,
• adjacent,
• horizontal,
• size,
• gothic,
• prepared,
• operational,
• accessible,
• permanent,
• trim,
• fixed,
• symmetrical,
• large,
• outdoor,
• fine,
• decorative,
• external,
• over,
• underground,
• conventional,
• important,
• close,
• rectangular,
• epidermal,
• developing,
• circular,
• mechanical,
• fleshy,
• typical,
• larger,

Simple categories matching outer:

• clothing,
• elements,
• box,
• opening,
• garment,
• space,
• layer,
• clothes,
• stressor,
• position,
• jacket,
• organ,
• package,
• block,
• part,
• surface,
• item,
• system,
• case,
• force,
• tissue,
• change,
• sense,
• characteristic,
• accoutrement,
• muscle,
• coat,
• container,
• fabric,
• object,
• appearance,
• circle,
• boundary,
• extremity,
• footwear,
• atmosphere,
• material,
• world,
• structure,
• control,
• attribute,
• shell,
• face,
• skin,
• body,
• integument,
• cloth,
• appendage,
• shape,
• gear,
• cap,
• piece,
• condition,
• area,
• mirror,
• disturbance,
• danger,
• ware,
• wall,
• packaging,
• equipment,
• power,
• article,
• coating,
• covering,