A word is said to be autological if it describes itself. This can be a property of both nouns and adjectives; for example, "noun" is a noun and "pentasyllabic" is pentasyllabic.
We can also construct what one might term "autological loops"- closed sequences of words that describe each other. As an example, a loanword is a word borrowed verbatim from a foreign language, such as "kindergarten", and a calque is a borrowed term that has been translated, such as "beer garden" (from "Biergarten"). Interestingly, "loanword" is a calque (from the German "Lehnwort") and "calque" is a loanword (from the French "calque"). Thus, "calque" and "loanword" form an autological loop.
(While loops of adjectives are possible, often these become subjective and depend on shades of meaning. For example, "long", "terse", and "diminutive"- "long" is terse, "terse" is diminutive, and "diminutive" is long. But what does it mean for a word to be long? Does 10 letters really qualify? Can a word truly be said to be terse, or can that only be said of a sentence? Because of these issues, we'll be ignoring adjectival loops.)
Now, my question is this: are there autological noun loops longer than 2, and if so, what is the longest one that can be formed?