Modifiers matching panel:

• structural,
• wooden,
• individual,
• special,
• tall,
• movable,
• narrow,
• exterior,
• sliding,
• trim,
• nonstructural,
• rigid,
• heavy,
• hard,
• flat,
• transparent,
• thin,
• vertical,
• semirigid,
• governmental,
• decorative,
• plastic,
• regulatory,
• solar,
• independent,
• supporting,
• fixed,
• metal,
• large,
• local,
• unwanted,
• big,
• moving,
• over,
• architectural,
• moveable,
• interior,
• clear,
• wide,
• flexible,
• major,
• horizontal,
• framed,
• down,
• expert,
• visible,
• external,
• artificial,
• retractable,
• automotive,
• inside,
• hollow,

Simple categories matching hollow:

• tree,
• beads,
• article,
• carrier,
• object,
• receptacle,
• particle,
• viscera,
• thing,
• ceiling,
• structure,
• part,
• glass,
• item,
• organs,
• cylinder,
• jewelry,
• form,
• protuberance,
• body,
• pole,
• utensil,
• shell,
• construction,
• organ,
• bones,
• implement,
• animal,
• passage,
• vessel,
• cavity,
• handgrip,
• pipe,
• container,
• product,
• dish,
• stem,
• surface,
• glassware,
• area,
• panel,
• material,
• piece,
• tubing,
• polyhedron,
• component,
• ball,
• tissue,
• sphere,
• fiber,
• reed,
• feature,
• instrument,
• bird,
• viscus,
• region,
• needle,
• formation,
• shape,
• plant,
• wood,
• tube,
• shaft,
• wall,
• conduit,
• ware,
• bone,
• space,
• section,
• fibre,
• assembly,