SEO for blog-like or dictionary-like website

There is a search box on my website. You can search any article on it by providing a keyword.

The problem is those articles can not be indexed by search engine, because there's no link to them from everywhere. And there are too many of them (~1000) to put on navigation bar. And I don't want my users to see a whole list of them (They can only search by keyword). But I do want google search engine to index all of them. Any way to do this?