Modifiers matching formation:

• geological,
• monolithic,
• geographical,
• rare,
• geologic,
• moving,
• stable,
• social,
• spatial,
• galactic,
• pointed,
• territorial,
• defensive,
• natural,
• rocky,
• interesting,
• smaller,
• elastic,
• impressive,
• molecular,
• active,
• structural,
• military,
• organic,
• conical,
• sacred,
• underground,
• acid,
• porous,
• conceptual,
• larger,
• complex,
• hard,
• intricate,
• unusual,
• sticky,
• polygonal,
• cambrian,
• individual,
• salt,
• calcareous,
• formal,
• organized,
• discrete,
• tropical,
• sedimentary,
• abrasive,
• siliceous,
• spiritual,
• mental,
• strange,
• nearby,
• ancient,
• dense,
• geographic,
• diverse,
• ideological,
• symbolic,
• national,
• personal,
• uniform,
• permeable,
• unstable,
• solid,
• weak,
• soft,
• exterior,
• key,
• christian,
• historical,
• igneous,
• popular,
• harder,
• past,
• artistic,
• cultural,
• traditional,
• impermeable,
• pedestrian,
• impersonal,
• large,
• homogeneous,
• regular,
• political,
• hollow,
• strong,
• vertical,
• virtual,
• deep,
• geometric,
• star,
• up,
• volcanic,
• typical,
• plastic,
• crystalline,
• special,
• pathologic,
• subsurface,
• impervious,
• tall,
• driving,
• beautiful,
• thick,
• standard,
• softer,
• medium,
• geophysical,
• coastal,
• earthen,
• massive,
• small,
• morbid,
• underwater,
• particular,
• unconsolidated,
• glacial,
• unique,
• surrounding,
• separate,
• major,
• offer,
• internal,
• quaternary,
• undesirable,
• common,

Simple categories matching hollow:

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