積ん読tsoon-DOH-koo[tsɯndokɯ]
buying books and letting them pile up unread — book-hoarding
Closest in English: book-hoarding, bookhoarding, book-piling. None of them covers it.
The word is a Meiji-era pun: tsunde oku, to pile up and leave, with doku, reading, tucked in at the end. Japanese attaches no shame to it; the pile simply exists, and grows. English book people have lately adopted it alongside their own coinage, book-hoarding.
Contains the answers. If you want to play the word yourself first, leave this closed.
Harder than most words so far.
Round two, literally, was where most points went.