The practice of acquiring books but letting them pile up without reading them.
A combination of the Japanese terms for "pile up" and "read", and dates back to 19th century Japan (source).
It was a miniature epiphany for me when I realized that the hobby of acquiring books was very different and only superficially related to my hobby of reading books.
This thick line of separation is helpful to recognize in other areas of our lives — drafting smart daily todos Is unrelated to executing those items, learning a new skill different from performing that skills, and making friends different from maintaining friendships. We would all do well to remember to give ourselves a break on thinking one always follows the other. Those books in the pile are not a sign of defeat, but of a hobby well-fed.