Daat Mikra

The Daat Mikra series on all the books of the Tanach provides an excellent source of etymological material. Each book's commentary is written by a different scholar:

Yehuda Kiel - Bereshit, Yehoshua, Shmuel, Melachim, Hoshea, Ovadia, Mishlei, Daniel (with Shmuel HaCohen), Divrei HaYamim

Amos Chacham - Shmot, Yishayahu, Yoel, Amos, Tehilim, Iyov, Shir HaShirim, Ester

Mordechai Zer-Kavod - Hagai, Zecharia, Malachi, Mishlei, Kohelet, Ezra, Nechemia

Menachem Bula - Vayikra, Yirmiyahu, Nachum, Habakuk, Tzefania

Yechiel Tzvi Moskowitz - Bamidbar, Yechezkel, Eicha

Elyakim Ben-Menachem - Yona

Feivel Meltzer - Rut

Yehuda Elitzur - Shoftim

Moshe Zeidel - Micha

Aharon Mirsky - Devarim

One thing that's always impressed me about the Daat Mikra series is the way they've made all the commentaries fit well, even though they're by different authors over the course of many years. When I'm trying to find the meaning or origin of a word, I'll often look at the Daat Mikra commentary on every instance of the word. I can't recall one example where I could say that one author had approach A, and a different author had approach B.