Modifiers matching fuel:

• safe,
• consumable,
• solid,
• liquid,
• finished,
• combustible,
• secondary,
• usable,
• expensive,
• precious,
• common,
• organic,
• homogeneous,
• practical,
• dry,
• harmful,
• conventional,
• light,
• traditional,
• residual,
• down,
• manufactured,
• major,
• particular,
• reactive,
• lighter,
• dense,
• gaseous,
• herbaceous,
• refined,
• physiological,
• dirtier,
• explosive,
• dirty,
• renewable,
• domestic,
• main,
• supporting,
• abrasive,
• artificial,
• special,
• chemical,
• oxidizable,
• vaporizable,
• ignitable,
• simple,
• ordinary,
• needed,
• unprocessed,
• automotive,
• available,
• intermediate,
• benign,
• unconventional,
• cryogenic,
• off,
• loose,
• extra,
• suitable,
• fibrous,
• several,
• indigenous,
• damaging,
• residential,
• individual,
• raw,
• technical,
• competitive,
• small,
• particulate,
• key,
• unhealthy,
• dangerous,
• wet,
• dead,
• powdered,
• future,
• commonplace,
• flammable,
• nonrenewable,
• supplementary,
• thinner,
• difficult,
• hard,
• inexpensive,
• fine,
• real,
• biological,
• familiar,
• heavier,
• macromolecular,
• single,
• compressible,
• taxable,
• vehicular,
• corrosive,
• cheap,
• local,
• strategic,
• rich,
• essential,
• inhomogeneous,
• granular,
• modern,
• metabolic,
• efficient,
• typical,
• odd,
• diverse,
• hazardous,
• basic,
• useful,
• mundane,
• cleaner,
• abundant,
• propellant,
• fluid,
• valuable,
• destructive,
• pure,
• normal,
• standard,
• medical,
• motor,
• nuclear,
• supplemental,
• discrete,
• possible,
• environmental,
• volatile,
• auxiliary,
• nonwoody,
• new,
• soluble,
• old,
• foreign,
• smaller,
• appropriate,
• important,
• unwanted,
• thermal,
• synthetic,
• complex,
• base,
• heavy,
• advanced,
• vegetative,
• direct,
• separate,
• convenient,
• inflammable,
• porous,
• uniform,
• alternative,
• specialized,
• sensitive,
• innovative,
• indoor,
• costly,
• compressed,
• actual,
• beneficial,
• natural,
• sustainable,
• toxic,
• carbonaceous,
• primary,
• regular,
• friendly,
• up,
• commercial,
• desirable,
• exotic,
• starting,
• miscellaneous,
• nonpolar,
• clean,
• industrial,

Simple categories matching cleaner:

• fuel,
• energy,
• builder,
• vehicle,