Use the and not connector to find documents in which a search word or phrase is to be excluded.

For example, the following search finds documents where the word "capital" occurs but the word "gains" does not.

capital and not gains

Because the exclusion covers the entire document, in this example, a document would be excluded if the word "gains" appears anywhere in the document.

You can exclude documents containing multiple words this way:

capital and not gains and not improvements

This example finds documents where the word "capital" occurs but the words "gains" and "improvements" do not.