Nouns are a lie, and the objects they refer to are nothing but an arrangement of simple, atomic components having a set of qualities we expect about that kind of object. They are a mental construct! Thus, their definition is ambiguous and leads to paradoxes (us humans being messy and imprecise, what a surprise). In fact, these nouns should be considered more like adjectives: chairs would be not a thing per se, but a blob of subatomic particles structured in a chairy way.
If it looks like a duck, swims, and quacks like a duck, then it's not a duck, but it is arranged duck-wise.