積ん読
つんどく
tsundoku
= the habit of buying books and letting them pile up unread
積ん読 names a very specific and very relatable failing: the books you bought with every intention of reading, now stacked on the nightstand, gathering dust and a little guilt.
積ん読 describes acquiring reading material, especially books, and letting it accumulate without ever reading it. It is gently self-mocking rather than harsh; people use it to confess their own growing stacks with a rueful smile. The word captures not just the pile itself but the whole comfortable habit of buying faster than you read, a state many book lovers know intimately.
積ん読 is almost always used about yourself in a lighthearted, confessional way, so it rarely sounds like an accusation. Note that it covers physical books most naturally, though people now extend it jokingly to unread e-books and saved articles. The reading つんどく is fixed; do not try to read 読 here as the usual よ.
The word is a pun. 積む means to pile up or stack, and 読 is the read character from 読む (to read). The phrase plays on 積んでおく (to stack and leave), with おく compressed so it echoes 読, the very thing the books are not getting. So 積ん読 literally hints at stacking books up to read, someday.
Casual / Social Media
また本を三冊買っちゃって、完全に積ん読が増えていく。
Mata hon wo sansatsu kacchatte, kanzen ni tsundoku ga fuete iku.
I bought three more books, so my tsundoku pile just keeps growing.
Everyday use
連休こそ積ん読を崩そうと思っていたのに、結局寝て終わった。
Renkyuu koso tsundoku wo kuzusou to omotte ita no ni, kekkyoku nete owatta.
I meant to finally chip away at my tsundoku over the long weekend, but I just slept instead.
Formal / Cultural context
積ん読という言葉は、読書を愛する人々の正直な習性をよく表している。
Tsundoku to iu kotoba wa, dokusho wo aisuru hitobito no shoujiki na shuusei wo yoku arawashite iru.
The word tsundoku nicely captures an honest habit of people who love reading.
積ん読 dates back to at least the Meiji era, when it began as a bit of bookish wordplay, and it has stayed popular because the experience it describes never goes out of style. It speaks to a culture that prizes books and reading while quietly acknowledging that desire and follow-through do not always match. The humor is forgiving: owning unread books is treated as a charming weakness, not a moral failure.
In recent years 積ん読 has drawn international attention as one of those Japanese words that seems to name a feeling other languages left unlabeled. Readers around the world recognized their own toppling stacks in it, and the term now circulates in English-language book communities, often kept in its original form because no single English word quite fits.