Modifiers matching impurity:

• physical,
• micro,
• fine,
• mobile,
• airborne,
• absorptive,
• nonpolar,
• harmless,
• polar,
• initial,
• coarse,
• ionic,
• homogeneous,
• microscopic,
• volatile,
• light,
• inorganic,
• gaseous,
• common,
• mental,
• insoluble,
• organic,
• up,
• stubborn,
• atmospheric,
• natural,
• separate,
• heavier,
• lighter,
• unwanted,
• mechanical,
• minor,
• solid,
• biological,
• small,
• suspended,
• damaging,
• chemical,
• dilute,
• lightweight,
• out,
• active,
• dissolved,
• desirable,
• anionic,
• colloidal,
• interfering,
• hazardous,
• reactive,
• undesired,
• fluid,
• soluble,
• smaller,
• little,
• sticky,
• visible,
• possible,
• random,
• ordinary,
• particulate,
• unavoidable,
• environmental,
• residual,
• off,
• corrosive,
• minute,
• heterogeneous,
• harmful,
• foreign,

Simple categories matching microscopic:

• object,
• organism,
• creature,
• dimension,
• cell,
• change,
• particle,
• critter,
• fauna,
• eukaryote,
• animal,
• protoctist,
• allergen,
• system,
• mechanism,
• irregularity,
• groove,
• host,
• entity,
• substance,
• flaw,
• form,
• algae,
• pattern,
• feature,
• contaminant,
• germ,
• space,
• machine,
• parameter,
• event,
• structure,
• plant,
• particulate,
• property,
• theory,
• filament,
• movement,
• bug,
• zone,
• impurity,
• difference,
• parasite,
• pollutant,
• body,
• medium,
• substrate,
• details,
• material,
• epiphyte,
• agent,
• pest,
• prey,
• pathogen,
• insect,
• detritus,
• clue,
• process,
• volume,
• sediment,
• instrument,
• plankton,
• defect,
• fiber,
• thing,
• transport,
• character,
• procedure,
• macromolecule,
• molecule,
• length,
• imperfection,
• phenomenon,
• part,
• invertebrate,
• unit,
• virus,
• quantity,
• information,
• force,
• arthropod,
• roundworm,
• deformation,
• engine,
• subject,
• state,
• level,
• world,
• characteristic,