Modifiers matching fuel:

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

Simple categories matching unconventional:

• material,
• medium,
• document,
• fibre,
• host,
• illustration,
• structure,
• surface,
• instrument,
• carrier,
• construction,
• mixture,
• literature,
• livestock,
• instrumentation,
• outfit,
• solvent,
• location,
• means,
• animal,
• weapon,
• floor,
• metal,
• fuel,
• source,
• fluid,
• tool,
• place,
• item,
• area,
• fiber,
• substrate,