In Ueda's translation of The Nightingale, which I am currently going through for a future analysis, I encountered this interesting paragraph:
Nagai biroudo no maku to, atsui kinran to wo kaketa, bibishii onshinjo no naka de, shachikowatte, iroaozame, yokotawatte iraserareta dake na no da.
"Long curtains of velvet, rich columns of gold hung in the middle of the Imperial Bedchambers, His Majesty lied there rigidly strung out and turning pale awaiting the danger."
I noticed that the kanji for "velvet," 天鵞絨 here given in the original the furigana biraudo (びらうど), but corresponding to modern orthography's biroudo, did not match the kana at all. In fact this led me onto researching the term.
Literally meaning "heavenly Goose's wool-cloth," but more properly "swan wool," it was term borrowed in Japanese from Chinese, read as tengajuu and came to mean "velvet," as Wikitionary saith:
The 1734 work 本朝世事綺談 (Honchō Seji Kidan, “Embellished Tales of Everyday Japan”; also listed as 本朝世事談綺, with the last two characters swapped) describes this kanji spelling as arising from how velvet shines and shimmers in a way reminiscent of a swan's plumage: 天鵞(tenga, “swan”, obsolete) + 絨(jū, “thick fabric”).
Thus, the term was used to describe this cloth's cygnine qualities and was later given the Portugues word veludo as the standard reading, rendered as biraudo and later biroudo in modern orthography, since, quoting Wiktionary:
The spelling is from the tengajū reading, ultimately from Chinese. The reading ビロード(birōdo) is from Portugueseveludo(“velvet”). The term was borrowed when Portuguese traders and missionaries first introduced velvet to Japan in the 1500s.
Hence it came via Portuguese missionaries and merchants from the same way as the terms tempura (tempora) and several other loan words came into the Japanese lexicon, not just from Portugal, but also from the Netherlands. These, too, have been and still are spelled in their ancient kanji-fied spellings, e.g. 天麩羅 ("heavenly wheat silk") for tempura - what now is known as a traditional Japanese dish, though more commonly written as 天ぷら, using hiragana for the last two kanji.
The phenomenon of assigning irregular readings or characters to words is broadly called "ateji", but this is erroneous. More properly there are:
Ateji (当て字, "purposeful characters") - Using the kanji for their sound when writing a word, hence tempura.
Jukujikun (熟字訓, "character compound reading") - Using kanji for their meaning and assigning them an irregular reading, hence biroudo. Also known as gikun ("artificial reading").
Thus venturing ever further from my analysis of the fairy-tale and into another proverbial leporine dwelling,
This could very well become a new blog-series in terms of irregular character/reading words. "Could," I stress, since I also am having plenty of other projects in the works and on hold.