The abbreviation "cf." stands for "compare" and is often used to direct the reader to a related concept or idea. However, there are a few synonyms for this word that can be used interchangeably. One of the most common replacements for "cf." is "see," which works well when directing the reader to a specific page, section, or paragraph. Another synonym for "cf." is "refer to," which is a little more precise and can be useful when directing the reader to a specific source or text. Finally, "check out" is another possible synonym for "cf.," although it is less commonly used and may not be appropriate in more formal writing contexts.