Modifiers matching duck:

• marine,
• jealous,
• common,
• tenacious,
• slobbery,
• larger,
• bullying,
• optimistic,
• boastful,
• paranoid,
• insecure,
• pushy,
• here,
• indigenous,
• native,
• large,
• lisping,
• breeding,
• rare,
• zany,
• small,
• short-tempered,
• smaller,
• determined,
• domestic,
• aggressive,
• wild,
• daffy,
• unusual,
• brash,

Simple categories matching rare:

• organism,
• commodity,
• metal,
• animal,
• recording,
• duck,
• tree,
• material,
• abnormality,
• earth,
• gas,
• bird,
• wildflower,
• tumor,
• mineral,
• extra,
• error,
• anuran,
• event,
• wood,
• item,
• crystal,
• flower,
• pathology,
• gemstone,
• predator,
• species,
• malignancy,
• circumstances,
• delicacy,
• gem,
• character,
• creature,
• disaster,
• fish,
• critter,
• virus,
• jewel,
• ingredient,
• complication,
• instrument,
• meat,
• flora,
• group,
• taxon,
• fibre,
• community,
• occurrence,
• invertebrate,
• solid,
• armor,
• deposit,
• entity,
• survivor,
• mutation,
• weapon,
• phenomenon,
• stuff,
• cause,
• oxide,
• antelope,
• society,
• weed,
• case,
• dyscrasia,
• vertebrate,
• mammal,
• anaemia,
• form,
• finch,
• process,
• essence,
• relative,
• reptile,
• thing,
• defect,
• seabird,
• location,
• mishap,
• disorder,
• constituent,
• source,
• betaine,
• document,
• substance,
• pet,
• harm,
• pathogen,
• problem,
• intervention,
• trade,
• drug,
• hazard,
• monster,
• mollusc,
• spirits,
• artifact,
• infection,
• resource,
• raptor,
• monotreme,
• quality,
• treasure,
• instance,
• reaction,
• monument,
• chemical,
• stone,
• art,
• disease,
• salamander,
• dragon,
• herb,
• fruit,
• ungulate,
• native,
• kind,
• compound,
• formation,
• article,
• condition,
• trait,
• waterbird,
• food,
• plant,
• illness,
• fauna,
• butterfly,
• wine,
• lesion,
• antiquity,
• component,
• medium,
• coin,
• foodstuff,
• allergen,
• symptom,
• danger,
• feature,
• neoplasm,
• insect,
• hardwood,
• unit,
• language,
• works,
• alkali,
• mushroom,
• waterfowl,
• dragonfly,
• hominid,
• bauble,
• nester,
• element,
• vegetable,
• amphibian,
• spice,
• situation,
• book,
• car,
• product,
• atom,
• object,
• substrate,
• shape,
• disturbance,
• cat,
• vehicle,
• tumour,
• merchandise,
• outcome,
• feline,
• building,
• cancer,
• cell,
• piece,
• endemic,
• carnivore,