yavan

I hadn't really noticed before, but the Hebrew word for Greece, יוון yavan, is related to the name of one of the ancient Greek tribes, the Ionians. As Klein writes:

A blend of יון, name of a son of Shem son of Noah (see Genesis 10:2) and orig. Greek Iaon, gen. Iaonos contracted into Ion, gen. Ionos (=Ion), ancestor of the Ionian race. 

The gemara (Yoma 10a) identifies a number of Noach's descendants with peoples of the region (such as Tiras with Thrace, and Madai with Macedonia), but says that Yavan is the (understood) meaning - e.g. Greece.

In addition to the mention in Bereshit, the word also appears in Yeshayahu (66:19), Yoel 4:6), Yechezkel (27:13, 19), Zecharya (9:13), Divrei Hayamim I (1:5,7) and Daniel (8:21, 10:20, 11:2).

The Ionians crossed the Aegean sea and settled the west coast of Asia Minor, in today's Turkey. Besides Hebrew, many other languages to the east of the Greeks (Akkadian, Sanskrit) used a form of Ionia to refer to Greece, since this was the first tribe they encountered.