Modifiers matching river:

• special,
• fast,
• perennial,
• larger,
• major,
• small,
• beautiful,
• nearby,
• large,
• clear,
• sensitive,

Simple categories matching fast:

• athlete,
• object,
• prey,
• mammal,
• person,
• equipment,
• terrorist,
• component,
• vessel,
• signal,
• killer,
• hero,
• animal,
• hacker,
• game,
• industry,
• criminal,
• event,
• meal,
• rebel,
• convict,
• soldier,
• sport,
• loop,
• picture,
• thief,
• river,
• car,
• predator,
• loner,
• racer,
• activity,
• conveyance,
• sportsman,
• cyclist,
• fugitive,
• messiah,
• item,
• boat,
• medium,
• entity,
• captain,
• bird,
• particle,
• sensor,
• motion,
• ship,
• creature,
• thing,
• carnivore,
• assistance,
• bus,
• fire,
• block,
• change,
• means,
• structure,
• system,
• move,
• action,
• activation,
• metal,
• food,
• memory,
• hound,
• subject,
• projectile,
• motorcycle,
• sound,
• insect,
• shark,
• vehicle,
• doctor,
• craft,
• adventurer,
• transport,
• android,
• phenomenon,
• delivery,
• spy,
• machine,
• fish,
• data,
• warrior,
• bug,
• device,
• process,
• storage,
• weapon,
• fixing,
• problem,
• fare,
• gas,
• cat,
• critter,
• reaction,
• movement,
• storm,
• quarry,