noun
old work; previously published book
Refers to a book or written work published in the past, often by the same author. Contrasts with 新著 (new work).
See also: 新著
この論文は旧著の内容を発展させたものです。
This paper develops the content of my previous work.
旧著の改訂版が来月出ます。
A revised edition of the old book will be published next month.