Defining fundamental terms of existence is challenging because they are the basic building blocks of understanding and cannot be broken down further. They themselves are the foundations used to explain, like trying to describe color to a blind person.The words that exist today, have definitions that were assigned to them at birth, throughout history their original meaning isn't always retained.While it's important to be aware of the evolution of the meaning of words, to be able to accurately understand historical documents using these terms,It is also important to have clear and practical definitions that modern society understands and agrees upon.A person sharing the definition of a word, is always sharing their subjective perception.They can never be wrong about their subjective perception.The mass can disagree with the definition if it does not synchronize with their own perception.Which is why when we wish to define a term to be agreed upon, it must either align with the perception of the rest, or they must be willing to reshape their understanding of the term when they encounter or use it in their life.