also: はだかほん · らほん
noun
used book without original cover or box
Refers to a secondhand book that is missing its original dust jacket, slipcase, or box. Common in used-book contexts.
この裸本はカバーがありませんが、中身はきれいです。
This used book is missing its dust jacket, but the inside is clean.
古本屋で裸本を安く買った。
I bought a book without its original cover cheaply at a used bookstore.
古本 is a general term for a used book, while 裸本 specifically refers to one missing its original cover or box.
Compound of 裸 (はだか, 'naked') and 本 (ほん, 'book'), literally 'naked book'. The exact origin is uncertain, but it likely arose in used-book circles to describe books lacking their original protective covers.