Meshech is named as a son of Japheth in Genesis 10:2 and 1 Chronicles 1:5, and as a son of Shem in 1 Chronicles 1:17.
Meshech is named with Tubal as a principality of the prince of Gog and Magog in Ezekiel 38:2 and 39:1, apparently considered a Japhetite tribe, identified by Flavius Josephus with the Cappadocian Moschoi with the Biblical Japhetic tribe descended from Meshech in his writings on the Genealogy of the Nations in Genesis 10.
Nations Descended from Noah
1 These are the generations of the sons of Noah, Shem, Ham, and Japheth. Sons were born to them after the flood.
2 The sons of Japheth: Gomer, Magog, Madai, Javan, Tubal, Meshech, and Tiras. 3 The sons of Gomer: Ashkenaz, Riphath, and Togarmah. –Genesis 10:1-3
Genesis 10:1-3 This chapter shows concerning the three sons of Noah, that of them was the whole earth overspread. No nation but that of the Jews can be sure from which of these seventy it has come. The lists of names of fathers and sons were preserved of the Jews alone, for the sake of the Messiah. Many learned men, however, have, with some probability, shown which of the nations of the earth descended from each of the sons of Noah To the posterity of Japheth were allotted the isles of the gentiles; probably, the island of Britain among the rest. All places beyond the sea from Judea are called isles, Jeremiah 25:22. That promise, Isaiah 42:4, The isles shall wait for his law, speaks of the conversion of the gentiles to the faith of Christ.