Modifiers matching residue:

• finer,
• herbaceous,
• agricultural,
• nonvolatile,
• hydrophobic,
• reactive,
• essential,
• alkaline,
• fresh,
• woody,
• organic,
• sticky,
• solid,
• basic,
• off,
• charged,
• unwanted,
• harmless,
• chemical,
• aromatic,
• inert,
• multiple,
• undesired,
• toxic,
• biochemical,
• conventional,
• explosive,
• infectious,
• harmful,
• insoluble,
• major,
• urban,
• valuable,
• fine,
• vegetative,
• polymeric,
• poor,
• small,
• side,
• undesirable,
• dangerous,
• light,
• larger,
• hard,
• binding,
• large,
• loose,
• noxious,
• key,
• electronegative,
• fibrous,
• carcinogenic,
• industrial,
• viscous,
• bulky,
• acidic,
• wet,
• neutral,
• inorganic,
• aliphatic,
• hydrophilic,
• lipophilic,
• volatile,
• interfering,
• active,
• dried,
• acid,
• particulate,
• miscellaneous,
• common,
• nonmetallic,
• greasy,
• dry,
• crystalline,
• stubborn,
• compressible,
• corrosive,
• inexpensive,
• possible,
• combustible,
• unrefined,
• internal,
• allergenic,
• biological,
• hygroscopic,
• smaller,
• heavy,
• uncharged,
• iron,
• refractory,
• fatty,
• structural,
• visible,
• heavier,
• flexible,
• sensitive,
• penultimate,
• antibiotic,
• botanical,
• useful,
• abundant,
• automotive,
• liquid,
• powdery,
• coarse,
• clean,
• tough,
• oily,
• functional,
• hazardous,
• cheap,
• dietary,
• metallic,
• animal,
• nonpolar,
• polar,
• soluble,
• carbonaceous,

Simple categories matching stubborn:

• condition,
• infection,
• imperfection,
• soil,
• stain,
• material,
• contaminant,
• substance,
• disease,
• item,
• impurity,
• deposit,
• residue,
• dirt,
• discoloration,
• coating,
• animal,