Enter encyclopedia in site search and link to several subject encyclopedias and a couple of general ones including Microsoft's Encarta. Again most of these are web guide encyclopedias, so with a jump jump you can usually find what you are looking for and a little more. Dictionaries, encyclopedias, yellow and white pages, more links for reference. Since 1870 Cobham Brewer's book has been a browser's joy, thankfully on line it is in its browsable form as well as usual search mode resulting with complete page not just single definition. Easily browsed or searched and 175 illustrations.
Definitions are a sentence or two, or a paragraph or two in length.
From dragons to Avalon to you name it world wide or time wise, there is a jump site here. Even the occasional dark ones.