🔼The name Tubal-cain in the Bible
The name Tubal-cain occurs only once in the Bible. He is one of three sons of Lamech the First (Genesis 4:22). His mother's name is Zillah and his sister's name is Naamah. His two half brothers are Jabal and Jubal. Their mother is called Adah.
The author of this story informs us that Jabal and Jubal are the "fathers" of all those who live in tents and have livestock, and those who play the lyre and pipe. To Tubal-cain, however, no patriarchy is ascribed. In stead the author says that Tubal-cain was "the forger of all implements of bronze and iron". This appears to indicate that the author figured that whoever lives in tents, keeps livestock of is a musician is an autonomous "son" of Jabal or Jubal, while whoever forges implements of bronze or metal is Tubal-cain himself.
The enigmatic nature of this paragraph continues when we realize that the patriarchies of Jabal and Jubal as well as the forging of metals were initiated in the godless era before the flood and by the godless lineage of Cain, and that they somehow survived the flood. Tubal-cain, after all, is the forger of all implements of bronze and iron, and although a very sporadic use of iron goes back to as far as 3000 BC, the iron age didn't commence until 1200 BC. And that is roughly half-way the book of Judges.
Note that our name occurs only in Genesis 4:22, where it is spelled once with a maqqep and once without (תובל־קין).
🔼Etymology of the name Tubal-cain
The name Tubal comes from the fertile root-verb יבל (yabal), meaning to carry or bring along, and note that the names of Tubal-cain's brothers, Jabal and Jubal, were derived from this same verb:
The second part of our name is the same as Cain and has to do with the following root group:
For a meaning of the name Tubal-cain, NOBSE Study Bible Name List reads Tubal The Smith for Tubal-cain and does not offer a translation for the separate name Tubal.
Jones' Dictionary of Old Testament Proper Names proposes Flowing Forth Of Cain for Tubal-cain.