Here is a diagram showing the different words we might use for the concept of “Walk.” The red color signifies home words, the blue signifies educated words, the purple signifies scholarly or scientific words, and the gray (like the dust in our attics) signifies rare or poetic words.
We use Level One words when we are speaking simply about general ideas. These are what one might call “irreducible” words–they cannot be reduced to simpler forms. They are our home language and everyone knows these words.
We use Level Two words when we want greater formality in our speech. Level Two words are common in official, impersonal environments. Most people understand them.
Level Three words from Latin or Greek are used in specialist settings like hospitals or graduate schools. Many people do not understand them, leading to difficulties in communication.
“Attic” words are our treasure chest, where we keep especially evocative words that seem to summon pictures to our minds. They are commonly used in fiction writing and poetry writing.