mehadrin and hadran

Today the word mehadrin מהדרין is generally associated with “super” kosher food (or even bus lines…). But the word actually first appears in the laws of Chanukah, in Masechet Shabbat 21b. There it says that if one lights a candle for each member of the household it is considered mehadrin, and if one adds (or subtracts) additional candles each night, it is considered hamehadrin min hamehadrin. There are two explanations to this term (see this article for an explanation of the significance of the two opinions). The one more popularly accepted is that of Rabbeinu Yitzchak in Tosafot, who say that the word derives from the root הדר, connected to the Biblical hadar, glory (cognate to the Akkadian adaru, and related to the Hebrew adir  אדיר - "noble"). According to Rabbeinu Yitzchak, when we add the additional candles, we glorify the mitzva, as we find with other mitzvot – the concept of hidur mitzva (beautifying the mitzva).

But Rashi has a different explanation. He says that mehadrin is related to the Aramaic verb הדר, meaning “to return”. This root is related, through familiar consonant changes, to the  Hebrew roots חדר (to surround, enclose; not actually related to חדר cheder - "room")  and  חזר (to go around, return, court). So Rashi explains that the person who is mehadrin, is "going around", pursuing the mitzvot. (See Brachot 53b for the parallel Hebrew expression - שמחזרים על המצוות - which is actually followed by an Aramaic translation: מהרדנא).

Another word with a similar debate as to its origin and meaning is hadran הדרן – from the passage read at the completion of a tractate of the Talmud: הדרן עלך .. והדרך עלן hadran alach ... v'hadrach alan.  (Eventually the passage itself became known as the "hadran", which led to the modern Hebrew meaning “encore”). Here, the common explanation is that it means “return”, and therefore the phrase means, “we will return to you, and you will return to us” (as mentioned by the Sefer HaEshkol). However, a number of researchers, such as Margolies (Olelot and Nitzotzei Or), Lieberman (Alei Ayin) and Sperber (Minhagei Yisrael vol 1; see an English summary in chapters 19 and 20 here) claim that hadran derives from hadar - “glory”, and so the phrase means, “our glory to you, and your glory to us.” This is both based on explicit mentions by earlier rabbis (such as the brother of the Maharal, Rav Chaim) as well as similar Talmudic passages: in Sukkah 45a it says that at the end of the Hoshanot on Sukkot, they would say to the altar: יופי לך המזבח - "beauty is yours, altar" and in Rosh Hashana 31a, it says that at the end of the Musaf sacrifices they would say הזיו לך - "the splendor is yours" (this phrase is actually included in the "hadran" of the Akedat Yitzhak). A similar phrase is also found in the Shir HaKavod ("Anim Zemirot") - פארו עלי ופארי עליו - "His glory is on me, and my glory is on him". In the end, Sperber concludes that the original meaning may have been "return", and the sense of "glory" was added in the times of the Geonim, so that the phrase intentionally carried both meanings.

One interpretation (Rashi, Kaddari) of the the unique biblical term hadurim הדורים (Yeshayahu 45:2) is that it means "curvy paths" - and is also related to the root הדר as "return, go around". The phrase from that verse -  וַהֲדוּרִים אֲיַשֵּׁר (straighten out the curvy paths, according to the explanation I quoted), is used in conversational Hebrew to mean "iron out the difficulties."

There’s no question about the origin of the word mahadura מהדורה, meaning “edition”. It comes from the Aramaic מהדורא, which is simply the Aramaic form of the Hebrew “machzor” מחזור. Both of which mean a “cycle, period of time”, and derive from the cognates הדר/חזר (see that usage in Bava Batra 157b). However, in modern Hebrew (even predating Ben Yehuda), mahadura came to refer to an edition of a printed work (now it also means a newscast), whereas machzor can mean any recurring event in the calendar, or the prayerbook used on holidays (originally it was interchangeable with siddur, but in time the siddur became designated for daily and weekly use). So you can actually use a particular mahadura of the machzor without the phrase seeming redundant…