וּלְנָעֳמִי אִשְׁתְּמוֹדַע לְגוּבְרַהּ גְּבַר גִּבָּר תַּקִּיף בְּאוֹרָיְתָא מִן יִחוּס אֱלִימֶלֶךְ וּשְׁמֵיהּ בּוֹעַז.
1. relative | מוֹדָע – The word "מוֹדָע" appears only in Rut (here, and see "מֹדַעְתָּנוּ" in 3:1) and in Mishlei 7:4, where it is parallel to the word "אחות", sister. The similar form "מְיֻדָּע" (matching the written "מידע", here) comes up a handful more times, and relates to the root "ידע", to know, taking the meaning of either a relative or acquaintance. [See, for example, Tehillim 31:12, 88:19, and Iyov 19:14.] Most commentators assume that in our verse the word refers to a kinsman, as the verse elaborates that Boaz was from the family of Elimelekh. See, though, Malbim and Hoil Moshe who maintain that it refers to a very close friend and confidante, one who knows the other very well. [If so, the verse shares that Boaz was both a friend and a relative of Elimelekh,]
2. mighty man of wealth | אִישׁ גִּבּוֹר חַיִל – The word "חַיִל" can refer to either wealth (as in Bereshit 34:29), strength and valor (as in Shemuel I 2:4 and 14:48), capability (as in Bereshit 47:6), or an army (as in Shemot 14:4). All the various meanings might be applicable here. Rut, too, will later be called an "אֵשֶׁת חַיִל" (Rut 3:11).
3. Boaz | בֹּעַז – The name appears to relate to the noun "עוז" meaning: "strength". The "בֹּ" might be short for "בו", rendering the name "strength is in him" or for "בוא" in which case the name might be translated: "may strength come". Boaz is identified as the judge Ivzan (see Shofetim 12:9) in Bavli Bava Batra 91a. The identification likely stems from the Midrashic tendency to identify lesser known characters (almost nothing is known about Ivzan) with more famous ones and the fact that our story is said to have happened "in the days that the judges judged". It is not clear, though, why one would identify Boaz with Ivzan specifically rather than any of the other minor judges. For other examples of character consolidation see here or the interactive module on the topic.