Toponymy
The name was originally that of an island — the name 'Barrai' can be traced back to 1190. This was later renamed 'Old Barrow', recorded as Oldebarrey in 1537, and Old Barrow Insula and Barrohead in 1577. The island was then joined to the mainland and the town took its name. The name itself seems to mean 'island with promontory', combining British barro- and Old Norse ey, but it is more likely that Scandinavian settlers simply accepted barro- as a meaningless name, and so added an explanatory Old Norse second element.
Read more about this topic: Barrow-in-Furness