Modifiers matching ground:

• hazardous,
• neutral,
• soft,
• weak,
• elevated,
• dangerous,
• vertical,
• high,
• under,
• disturbed,
• sandy,
• sized,
• hard,
• conductive,
• rough,
• mechanical,
• flat,
• loose,
• good,
• low,
• open,
• technical,
• grown,
• level,
• woven,
• particular,
• working,
• porous,
• wet,
• unstable,
• new,
• permeable,
• safe,
• bad,
• undisturbed,
• white,
• shiny,
• up,
• familiar,
• metal,
• dry,
• common,
• sacred,
• private,
• higher,
• over,
• routine,
• old,
• metallic,
• rocky,
• sensitive,
• irregular,
• stable,
• natural,
• softer,
• moist,
• firm,
• barren,
• electrical,
• artificial,
• coarse,
• holy,
• clean,
• durable,
• uncultivated,
• paved,
• slippery,
• rigid,
• heavy,
• waterlogged,
• off,
• difficult,
• clear,
• uneven,
• harder,
• convenient,
• unsecured,

Simple categories matching clean:

• jewel,
• item,
• sample,
• surface,
• thing,
• organs,
• area,
• debris,
• mixer,
• material,
• container,
• residue,
• fluid,
• sport,
• tubing,
• article,
• part,
• waste,
• service,
• object,
• linen,
• veggie,
• machine,
• hay,
• garment,
• substance,
• metal,
• amp,
• activity,
• air,
• equipment,
• vessel,
• plate,
• work,
• business,
• structure,
• building,
• textile,
• waterway,
• jar,
• lake,
• appliance,
• solvent,
• hydrocarbon,
• supply,
• effort,
• receptacle,
• ingredient,
• industry,
• apparel,
• product,
• space,
• energy,
• solid,
• feature,
• bird,
• gas,
• loan,
• clothing,
• utensil,
• gem,
• cloth,
• salt,
• territory,
• device,
• particle,
• brush,
• tool,
• piece,
• fun,
• location,
• room,
• club,
• green,
• procedure,
• bones,
• component,
• technology,
• corpus,
• extra,
• laundry,
• ground,
• instrument,
• aggregate,
• bottle,
• fiber,
• furniture,
• conduit,
• matter,
• audio,
• screen,
• inside,
• abrasive,
• uniform,
• semiconductor,
• lettuce,
• drape,
• place,
• gutter,
• meat,
• dressing,
• bedding,
• pollutant,
• property,
• fuel,
• source,
• sand,
• animal,
• paper,
• electricity,
• seed,
• atmosphere,
• fish,
• deposit,
• runoff,
• environment,
• contaminant,
• floor,
• wastewater,
• liquid,
• comestible,
• facility,
• gemstone,
• board,
• grain,
• food,
• fabric,
• fixture,
• soil,
• medium,
• stone,
• production,
• cylinder,
• design,
• artifact,
• aroma,
• line,
• sediment,
• system,
• substrate,
• stain,
• water,
• string,
• vegetable,