noun
Refers to an old handwritten copy of a text, especially a pre-modern manuscript or codex. Often used in historical, literary, or archival contexts.
この図書館には貴重な古写本が所蔵されている。
This library holds a valuable old manuscript.
研究者は古写本を比較して本文
The researchers compared old manuscripts to examine textual variations.
古書 means an old book (printed or handwritten), whereas 古写本 emphasizes that it is a handwritten copy.
Compound of 古 (old) + 写本 (manuscript, handwritten copy).