As an example let's take the free dictionary, very nice (guess what ??) dictionary site :)
In Firefox we can add a shortcut so we can speedy our browsing experience. See the example belowInstead going to the TheFreeDictionary site and then typing the word we want to look for (for instance, cake), just type tfd cake in firefox address bar! Simple like that! :)
In order to make this work we need to tell firefox that we want a shortcut named tfd (you can name it at your will) and that it must navigate to www.tfd.com/whatever-we-type-in-address-bar.
To do this, open bookmark manager (CTRL-B) add a new bookmark as follow:
(note the url: http://www.tfd.com/%s)
Press Add and you are done! Now just type tfd cake on firefox address bar!