Interesting question. I had a scan of the articles in other languages, on Wikipedia. Almost all the Latin alphabet languages use a variant of 'imaginary'. Icel

Interesting question. I had a scan of the articles in other languages, on Wikipedia. Almost all the Latin alphabet languages use a variant of 'imaginary'. Icelandic appears to be an exception, where it means cross-number. https://en.wiktionary.org/wiki/þvertala#Etymology https://en.wiktionary.org/wiki/þvertala#Etymology (I don't know non-Latin alphabets I can't tell you anything about them.)