What does Matthew 27:8 mean?

It doesn't necessarily follow that a tract of land used as a burial place for foreigners would be called the "Field of Blood." However, this land was bought using money Judas returned after suffering remorse for his betrayal of Jesus (Matthew 26:14–16; Matthew 27:3–7). The priests called it "blood money," recognizing its use for a tainted purpose, and chose not to use the coins in the temple (Deuteronomy 23:18). It's possible that the location acquired its nickname once the truth of what had happened became clear.

Another possible explanation comes from Acts 1:18–19. This gives more details about Judas' suicide. In an aside, Luke, the writer of Acts, indicates poetically that Judas bought the field in question—as it was his money that purchased it—and then states that his guts burst out as he fell. The result of the payment to Judas was the acquisition of the field. That was the fruit of his labor. It doesn't mean he completed the transaction himself. Luke's description does suggest, though, that perhaps the priests bought the potter's field because that's where Judas hanged himself.

Bible scholars suggest several explanations for the vivid end to Judas's hanging. It may be that after he died, nobody wanted to defile themselves by touching the body for a time and the sun caused Judas' body to quickly decompose, fall, and burst open. Or, perhaps, Judas hanged himself from a limb over a ravine, common in the area, and the branch gave way before or after his death. Or, most simply of all maybe, Judas simply fell to his death while attempting to hang himself.

In any case, the name "Field of Blood" connects to the tragic circumstances of its purchase.