Back when the Jews in the Old Testament were worshipping God, they spoke a language we call Hebrew. But, through a whole bunch of historical twists and turns, by the time Jesus was born, the common language of Judea was something called Aramaic.
Aramaic is very similar to Hebrew, but it’s still a different language. One way I heard it described is to compare them to the Romance languages of Europe. For example, Italian and Spanish are both very similar languages because they come from Latin. But they’re still different languages. It’s the same way with Hebrew and Aramaic, different languages, but very similar.
However, The Old Testament was written almost entirely in Hebrew, so the Jews needed some sort of translation to really understand it.
This is very similar to how the Catholic Church would have their services in Latin during the Middle Ages. At a time when no one spoke Latin as a native language, the Catholics still taught in Latin and then translated verses later. Many religious traditions throughout history have tried to hold on to ancient languages and difficult to understand writings.
So, the Jews came up with a solution for this language barrier. During their Synagogue services, one teacher would read a small section of scripture in Hebrew (think a verse or two), then some other guy would translate that into Aramaic for everyone in the crowd.
That other guy who would translate the Hebrew into Aramaic was something called a hammeturgem, literally “a translator”. And the translation he gave was called a Targum. You can see that root word Targum in the word hammeturgem.
However, the word in Hebrew can mean a little more than just “translate”. It can also more broadly mean “to interpret”. This is because the men who gave the translation into Aramaic would commonly add their own opinions of what the text actually meant.
For this reason, the Jews did not allow anyone to write down any Targumim (plural of Targum), so that no one would start treating them as equal with scripture. But, over the centuries, some Rabbis broke this rule and wrote down massive Targumim, or interpretations, of The Old Testament.
We also see this word used in Ezra 4:7, when it says:
“The letter was written in Aramaic and translated.”
That word “translated” is a form of the word Targum. And, if you read Ezra, you’ll see a footnote telling you that 4:8-6:18, which quotes the letter referenced in 4:7, is in Aramaic. This is one of the few sections of The Old Testament that was written in Aramaic rather than Hebrew.