N.B. The email exchange below may have been edited, e.g. to remove content not essential to the main point(s) or to standardize English spelling/grammar.
... A friend of mine and I have been looking into a few things and are a bit lost and need some scholarly help. ... The information we have is from a Bauer-Danker Lexicon [of Greek, and] I have included a scanned page... We want to understand the relationship between 3 words...
...we were [looking at a certain word], but then we noticed that the word before it and after it... are similar: "dust" and "earthy." But smack dab in-between these words are the Greek words for six hundred and sixty six. The question is, how are these words all related with each other? I mean, why would a number be in there with words that mean, well... dirt basically?
Thanks for your time, C.
The short answer is, they aren't at all related! The "word" you refer to, conveying the meaning 666, is not a word at all. Greek, like many ancient languages, used arbitrary letters to stand for numbers.
Let's say that, in English, we used D to stand for 600, E to stand for 60, and F to stand for 6. In text, then, we could write DEF (or FED) to mean "six hundred sixty-six," and achieve great textual economy vs. spelling out the full words naming the numbers as quoted above.
Your dictionary lists the 3 letters as if they constituted a word but, if you read closely, it also explains what is going on. Alphabetic sorting yields positions that do not, as in this case, suggest any similarity in meaning.