[brigandish]

It's a well known theory but it's most likely false[1], though there are several words imported to Japan via Portuguese that have long remained, such as the word for England, イギリス, which comes from the Portuguese for English (people), Ingles, which drives me a bit potty as it's used now to refer to the whole of the UK and I have trouble trying to distinguish England from Scotland et al when speaking with Japanese people.

Ironically, "Japan" is from an old Chinese word for Japan that was then imported to Europe… by those dastardly misnomerists of countries, the Portuguese!

[1] https://japanese.stackexchange.com/a/5481/10723

[jacobush]

In Sweden we often use "England" for the UK. But I always feel a little guilty when doing it.