Modifiers matching line:

• trim,
• flexible,
• central,
• straight,
• short,
• functional,
• adventurous,
• protective,
• vertical,
• several,
• electric,
• moving,
• curved,
• conductive,
• underground,
• geometric,
• additional,
• horizontal,
• metal,
• light,
• carved,
• black,
• major,
• long,
• deep,
• thematic,
• longer,
• irregular,
• personal,
• physical,
• fine,
• metallic,
• closed,
• nonmetallic,
• active,
• loose,
• facial,
• hidden,
• elongated,
• natural,
• parallel,
• special,
• ancillary,
• smaller,
• broken,
• new,
• simple,
• public,
• evocative,
• auxiliary,
• planar,
• sharp,
• pneumatic,
• melodic,
• operational,
• stock,
• elastic,
• continuous,
• profitable,
• heavier,
• digital,
• mechanical,
• base,
• identifiable,
• smooth,
• defined,
• dry,
• powerful,
• working,
• incoming,
• supporting,
• meaningful,
• particular,
• soft,
• periodic,
• private,
• linear,
• architectural,
• solid,
• sophisticated,
• real,
• medical,
• restricted,
• single,
• slow,
• electrical,
• extraneous,
• colored,
• fixed,
• secure,
• primary,
• off,
• larger,
• spectral,
• broadband,
• structural,
• molecular,
• overhead,
• departmental,
• wired,
• electronic,
• drawn,
• faint,
• outside,
• traditional,
• popular,
• fluid,
• hydraulic,
• clean,
• strong,
• domestic,
• thin,
• specified,
• external,
• ornamental,
• critical,
• peripheral,
• stable,
• dark,
• affected,
• up,

Simple categories matching underground:

• cavity,
• cavern,
• utility,
• structure,
• area,
• facility,
• supply,
• liquid,
• part,
• works,
• music,
• vegetable,
• harvester,
• installation,
• material,
• passage,
• line,
• fortification,
• object,
• improvement,
• housing,
• property,
• item,
• service,
• aquifer,
• location,
• tunnel,
• space,
• feature,
• container,
• obstruction,
• room,
• system,
• expanse,
• formation,
• shelter,
• place,
• life,
• equipment,
• world,
• conduit,
• tank,
• hydrocarbon,
• pest,
• stem,
• obstacle,
• reservoir,
• organ,
• band,
• cave,
• cable,
• fixture,
• group,
• wealth,
• fluid,
• excavation,
• activity,
• pipe,
• topic,
• building,
• relic,
• plant,
• enclosure,
• pipeline,
• conductor,
• storage,
• void,
• cistern,
• construction,
• opening,
• bunker,
• resource,
• work,
• treasure,
• development,
• duct,