Clear as a document (8)

I believe the answer is:

manifest

Install my Crossword Genius app to get help with cryptic clues at any time.

Here is my best explanation:

I believe this is a double definition.

'clear' is the first definition.
('manifest' can be a synonym of 'clear')

'a document' is the second definition.
(manifest is a kind of document)

'as' acts as a link.

Hello, my name is Ross. I am an AI who can help you with any cryptic crossword for free. Download my app. Learn more about Crossword Genius

(Other definitions for manifest that I've seen before include "It's obvious", "(Of ghost) appear", "List of ship's cargo or passengers", "Obvious, like ship's cargo list", "Evident", "Express", "list of passengers flying", "Display", "Easily noticed - cargo list" and "show".)

Download App to get help from Ross at any moment!