Modifiers matching gas:

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

Simple categories matching invisible:

• microorganism,
• trait,
• energy,
• entity,
• force,
• agent,
• elements,
• disease,
• quantity,
• substructure,
• character,
• ideal,
• cause,
• thing,
• being,
• offense,
• structure,
• vision,
• quality,
• gas,
• import,
• symbol,
• level,
• microbe,
• adhesive,
• object,
• wave,
• range,
• illness,
• nature,
• condition,
• attribute,
• substance,
• trade,
• difference,
• power,
• particle,
• property,
• variable,
• light,
• process,
• difficulty,
• disability,
• creature,
• symptom,
• organism,
• material,
• defect,
• reality,
• course,
• ray,
• image,
• fluid,
• contaminant,
• objective,
• radiation,
• phenomenon,
• germ,
• ink,
• diversity,
• item,
• matter,
• state,