Using Lexipedia you can visually map out words and concepts in a clean and friendly interface. No more thumbing through a dictionary, or fumbling through a single-word search; with Lexipedia you can see related words, synonyms, antonyms and fuzzynyms. And best of all, it's absolutely free!
serving as an essential component; "a cardinal rule"; "the central cause of the problem"; "an example that was fundamental to the argument"; "computers are fundamental to modern industrial structure"
(used especially of ideas or principles) deeply rooted; firmly fixed or held; "deep-rooted prejudice"; "deep-seated differences of opinion"; "implanted convictions"; "ingrained habits of a lifetime"; "a deeply planted need"