If you type words into the address bar of Mozilla Firefox, and the words do not look like a valid URL, then the words will be passed to the default search engine (Google in the case of Firefox) as search terms. For example, a string such as ‘whodat.dere’ will be parsed as a domain name to be resolved, but ‘whodat dere’ or just ‘whodat’ will be passed to the search engine.
I generally use the privacy-respecting search engine at www.startpage.com. How can that be made the default search engine so that words accidentally typed into the address bar do not get sent to Google? Easy! In the address bar, enter
about:config and confirm that you understand what you are doing. Search for the preference name (i.e., the entry) called
keyword.URL. Double-click on the preference name. When Firefox asks you to enter a string, type
https://www.startpage.com/do/search?query= and then click OK. It also makes sense to change the entry called
browser.search.defaultenginename to Startpage but, so far as I can tell, that is a purely cosmetic change.
The default search engine can be set to anything else you want. For example: