Modifiers matching ground:

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

Simple categories matching irregular:

• item,
• surface,
• condition,
• shape,
• soil,
• ground,
• dust,
• object,
• part,
• structure,
• organization,
• unit,
• phenomenon,
• pattern,
• polygon,
• connection,
• array,
• hours,
• set,
• payment,
• job,
• terrain,
• display,
• asterism,
• light,
• area,
• curve,
• component,
• holiday,
• form,
• line,
• cell,
• odor,
• wall,
• material,
• edge,
• solid,
• expense,
• place,
• border,
• commodity,
• system,
• space,
• week,
• particle,
• activity,
• occurrence,
• program,
• astigmatism,
• interval,
• work,
• event,
• obstruction,
• profile,
• period,
• flower,
• boundary,
• use,
• behavior,
• body,
• road,
• motion,
• shelter,
• feature,
• organ,
• original,
• substrate,