Modifiers matching gas:

• propellant,
• mobile,
• ordinary,
• rare,
• inert,
• under,
• special,
• respiratory,
• strong,
• combustible,
• oxidative,
• anthropogenic,
• hydrophobic,
• pure,
• noble,
• warming,
• single,
• flammable,
• essential,
• diamagnetic,
• hot,
• harmless,
• supplemental,
• safe,
• industrial,
• medicinal,
• heavier,
• diffusing,
• relativistic,
• radioactive,
• explosive,
• starting,
• toxic,
• cheap,
• available,
• medical,
• biogenic,
• edible,
• detrimental,
• oxidizable,
• polar,
• particular,
• expensive,
• electronegative,
• noxious,
• ionic,
• cryogenic,
• incombustible,
• unwanted,
• injurious,
• heated,
• benign,
• airborne,
• unique,
• impure,
• damaging,
• soluble,
• frozen,
• base,
• supporting,
• malodorous,
• inflammable,
• elemental,
• out,
• key,
• metal,
• small,
• monatomic,
• cold,
• relevant,
• number,
• incoming,
• acid,
• refrigerated,
• faster,
• convenient,
• environmental,
• compressible,
• nonflammable,
• carcinogenic,
• floating,
• mixed,
• paramagnetic,
• liquified,
• deadly,
• residual,
• stable,
• neutral,
• secondary,
• innocuous,
• poisonous,
• metabolic,
• harmful,
• traditional,
• tenuous,
• natural,
• additional,
• vesicant,
• liquefied,
• model,
• refrigerant,
• chemical,
• raw,
• dusty,
• passive,
• unstable,
• external,
• corrosive,
• real,
• invisible,
• hydrophilic,
• lighter,
• inorganic,
• nontoxic,
• vital,
• carbonaceous,
• reactive,
• divalent,
• active,
• auxiliary,
• irritating,
• ignitable,
• weak,
• monoatomic,
• suitable,
• desirable,
• artificial,
• mental,
• warm,
• rarefied,
• synthetic,
• unsaturated,
• critical,
• suffocating,
• technical,
• dense,
• important,
• absorptive,
• medium,
• miscellaneous,
• indoor,
• diatomic,
• obnoxious,
• basic,
• manufactured,
• thin,
• malign,
• abundant,
• complex,
• insoluble,
• moving,
• liquid,
• controlled,
• volatile,
• useful,
• familiar,
• dilute,
• organic,
• sulfurous,
• permanent,
• surrounding,
• valuable,
• separate,
• luminous,
• identifiable,
• clean,
• transparent,
• inexpensive,
• scientific,
• electropositive,
• common,
• noncombustible,
• minor,
• classical,
• extraneous,
• deleterious,
• fast,
• dry,
• simple,
• rich,
• dangerous,
• conductive,
• dissolved,
• supercritical,
• light,
• protective,
• ambient,
• foreign,
• lightweight,
• molecular,
• interfering,
• acidic,
• individual,
• saturated,
• working,
• major,
• atomic,
• heavy,
• commercial,
• consumable,
• buoyant,
• aggressive,
• automotive,
• atmospheric,
• alkaline,
• compressed,
• popular,
• off,
• supportive,
• conventional,
• beneficial,
• hazardous,
• nonpolar,
• undesirable,
• standard,
• fixed,

Simple categories matching clean:

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