In the Search Term Detail area (this is the expanded part when you click on a search term row), one of the buttons presented is called “Search Other Sites.”
Unlike the main Sources or online dictionaries that are able to be searched directly and in bulk (Oxford, Merriam Webster, etc…), these are online sources that don’t allow us to connect directly to their database. They may still provide the information you need, however, so this drop down list provides pre-built links to them.
For example, if your search term is “cameralism,” and it is not found in the main Sources, you can click one of the Other Sites links to check them. Clicking “Google Pronunciation” will open a new tab with Google search results for the phrase “pronounce cameralism.”
You can click on as many Other Sites as you would like and a new tab will open for each. Depending on your browser, you will probably have to click “allow popups” or a similar permission the first time you do this.