Why is the most well-known Jewish holiday called “Chanukah?” What is the origin of the name, and what are some of the deeper kabbalistic meanings behind it?

1. The name Chanukah was given in commemoration of the historical fact that the Jewish fighters rested - "chanu" (the FIRST THREE LETTERS of the word “Chanukah”) - from their battles against Syrian-Greeks on the 25th of Kislev. 25 is spelled out chof-heh - the FINAL TWO LETTERS of “Chanukah.” (source: Kol Bo; Abudraham; Tur; Ran)
2. The Hebrew word "chein" (the FIRST TWO LETTERS of the word “Chanukah”) denotes grace. Thus 'Chanukah' could be meant to allude that the Jewish warriors found Divine 'grace' on the 25th of Kislev. (source: Noam Elimelech)
3. One of the most direct explanations of the name Chanukah is that it is related to the dedication (“chanukah”) of the Altar, [a centerpiece of the Holy Temple in Jerusalem]… We learn in the Talmud (Avodah Zarah 52b) that the Hasmoneans removed and stored away the Altar-stones which the Greeks had polluted with idolatry, and had to build a new Altar. That is why the festival is called 'Chanukah' which means 'dedication.' (source: Maharsha to Shabbos 21b) See also: I Maccabees 4:44-9 and II Maccabees 10:2-4.
4. The name Chanukah refers also to the dedication of the Second Temple, which occurred on almost the same calendar date (see the Book of Chaggai 2:18). It is because of this consecration (“chanukah”) of the Second Temple that the miracle of the lights that happened in that season - generations later - is called Chanukah. (source: Rabbi Yaakov Emden)
5. The name also commemorates another dedication (“chanukah”) that nearly occurred on a 25th of Kislev, for it was on that date that work was completed on the Tabernacle - during the 40 years of Jewish wandering in the desert. Although the work was finished in Kislev, the Tabernacle was not dedicated then, for, as the Midrash records, God wished to combine the joy of the Tabernacle with Nissan - the month in which the Patriarch Isaac was born. Thus God (so to speak) “repaid the loss” to Kislev, in which the labor was actually completed, with the Chanukah of the Hasmoneans. Furthermore, it is for this reason that the Biblical chapter dealing with the sacrificial offerings brought by the Tribal princes at the dedication of the Tabernacle [Numbers ch. 7], forms the synagogue Torah readings during our 8 days of Chanukah. (source: Shibbolei HaLeket)
6. Homiletically there is an allusion in the Hebrew name Chanukah to the fact that we conduct ourselves on Chanukah in the manner advocated by the School of Hillel. Hillel holds that we begin on the first night with one light, and add additional lights on each of the subsequent nights. (As opposed to the practice of the School of Shammai, who begin with eight lights and subtract one light on each of the subsequent nights). The initials of Chanukah spell: “Eight Lights, and the Halachah follows the School of Hillel.” (source: Abudraham; Ateres Zekeinim; Pri Megadim)
7. Kabbalistically, at the time of the lighting of the Chanukah candles, there is a revelation of part of the “Ohr Haganuz,” the great light hidden away since the beginning of Creation - the light of Messiah. And that is why the festival is called Chanukah - because it is a spiritual preparation [“chinuch”] for our destined Redemption. (source: Bnai Yisas'char)

Reprinted with permission from InnerNet Magazine