To add a different search engine, perform a search in the address bar using that search engine (or a website that supports search, like a wiki site). Then go to Settings and more > Settings > Privacy and services > Address bar. The engine or website you used to search will now appear in the list of options you can select.

First, visit a search engine (or a website with a search feature). Chrome will automatically detect and add the search engine, if that site supports this feature. Next, right-click in Chrome’s location bar and select “Edit Search Engines”. Search engines from websites you’ve visited will appear in the “Other search engines” box.