ADV
随本文（或本书）附上;随信附上
Herewith means with this document, text, or book. You can use herewith in a letter to say that you are enclosing something with it.
例句
...the 236 revolutionary prisoners whose names are listed herewith...
236名革命囚犯，名单附在本材料中
I return herewith your papers.
我随信退还你的文件。