I decided to read about the words for Ginkgo in Japanese (as in Ginkgo biloba).
I was surprised to learn that Ginkgo comes from Japanese! According to Wikipedia, Engelbert Kaempfer, while writing the Amoenitatum exoticarum, read the kanji 銀杏 as ぎんきょう. He romanized this reading as Ginkjo, which was then unfortunately misprinted as Ginkgo, resulting in the spelling used in many Western languages today.
From the same article, I see that イチョウ is a common word for Ginkgo plants, apparently from the Chinese 鴨脚. It seems that this word was assigned to the kanji 銀杏 as a jukujikun reading, and we can see that both readings existed 300 years ago, because Kaempfer also transcribed イチョウ (as Itsjo).
In fact, 銀杏 has a third reading, ぎんなん. Similar to ぎんきょう, it appears that this reading was made by putting two on'yomi together: ぎん＋あん＝ぎんあん→ぎんなん. But here's what makes me curious about the difference between the readings: 大辞林 and 大辞泉 only list ぎんなん, not ぎんきょう. And 300 years ago, Kaempfer only transcribed ぎんきょう, not ぎんなん.
It seems that both ぎんきょう and ぎんなん mean the same thing (Ginkgo plants or seeds). But what is the relationship between the two readings?
- Did ぎんなん replace ぎんきょう, making the latter obsolete?
- Or are both readings still used?