rare book; unusual book
Refers to a book that is hard to find, out of print, or otherwise uncommon. Often used in bibliophile or antiquarian contexts.
I found a rare book at this secondhand bookstore.
彼の書斎には多くの珍書が並んでいる。
Many rare books are lined up in his study.
Compound of 珍 (chin, 'rare, unusual') + 書 (sho, 'book, document'). The reading is on'yomi.