The term originated in the Meiji era (1868–1912) as Japanese slang. It combines elements of tsunde-oku (積んでおく, to pile things up ready for later and leave) and dokusho (読書, reading books). It is also used to refer to books ready for reading later when they are on a bookshelf. As currently written, the word combines the characters for "pile up" (積) and the character for "read" (読).
A. Edward Newton is quoted as saying:
Even when reading is impossible, the presence of books acquired produces such an ecstasy that the buying of more books than one can read is nothing less than the soul reaching towards infinity ... we cherish books even if unread, their mere presence exudes comfort, their ready access reassurance.
- Brooks, Katherine (March 19, 2017). "There's A Japanese Word For People Who Buy More Books Than They Can Actually Read". The Huffington Post. Retrieved 16 October 2017.
- Tobar, Hector (July 24, 2014). "Are you a book hoarder? There's a word for that". Los Angeles Times. Retrieved 16 October 2017.
- "Tsundoku: The art of buying books and never reading them". BBC News. Retrieved 30 July 2018.
- ""Tsundoku," the Japanese Word for the New Books That Pile Up on Our Shelves, Should Enter the English Language". Open Culture. July 24, 2014. Retrieved 16 October 2017.
- "A quote on bibliomania"