Remembering what Deuteronomy means is easier to me than remembering how to spell it. It’s that tricky placement of the e and the u at the beginning that gets me every time.
The word Deuteronomy, interestingly enough, does not come from the original Hebrew “title” of the letter (which is basically the beginning of Deuteronomy 1:1 that says “These are the words…“). It actually has Latin (Deuteronomium) and Greek (Deuteronomion) origins. Each of these origins roughly translates to a meaning of “second law”.
Although it is a good literal translation, “second law” isn’t “necessarily” the best way to view the point of the word Deuteronomy, or the letter itself. It’s not a second law insomuch as it is a repeating of the law. A very good way to think about it is found in Deuteronomy 17:18 where you will find the Hebrew word “Mishneh” which means, in the context, “double, copy or repetition“. In other words, “Deuteronomy” is a repeating (Deuteros, or second) of the principals and points (Nomos, or law) that can elsewhere be found in was then the existing foundation of the Law.
In the Deuteronomy letter, Moses is very much concerned with the task of making sure the present generation understands what it is about to gain and why the previous generation did not possess it! He accomplishes this through quick history lessons and by placing an emphasis on the love and loyalty and obedience, as well as the warnings that are given about the lack of such, that God requires through the covenant he is making with them (Deuteronomy 6:4-9).
The above points are still pertinent today. Especially when you consider how the Hebrew writer emphasized a “deuteronomy” of these things in Hebrews 3, 4 amongst several other passages too.